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Un volume d'une capacité minimal 2009-01-05
Pauline pose la question :
je doit faire un volume d'une capacité minimal de 2500 cm 3 en quell matiere que ce soit
* un prisme a base pentagonale non réguliere
* une sphere
* stella octangula

Pierre-Louis Gagnon lui répond.
les données sont inconsistantes 2007-10-03
Mikee pose la question :
Bonjour, Je me casse la tete depuis ce matin et la je donne ma langue au chat. Je n'arrive pas a resoudre ce probleme. J'ai 30 agents qui appellent dans la journee et realisent 322 questionnaires (long+court) telephonique avec une duree moyenne de conversation 294 secondes. dans ces 322 qestionnaires : -ils realisent 313 questionnaires Long avec une duree moyenne de 317 secondes. -ils realisent 9 questionnaires Court avec une duree moyenne X. je cherche X.

((Interviews réalisées*Durée moyenne de conversation)-(Interviews réalisées avec la question Q2*Durée moyenne de conversation avec la question Q2))/(Interviews réalisées-Interviews réalisées avec question Q2)=Durée moyenne de conversation sans la question Q2

Q2=questionnaire Long

Claude Tardif lui répond.
5 points équidistants sur la surface d' une sphère 2005-08-15
Jean pose la question :
J' aimerais placer 5 points équidistants sur la surface d' une sphère. Si vous aviez une formule simple pour un néophyte, cela m' aiderais beaucoup.
Claude Tardif lui répond.
Les dimensions d'un rectangle 2001-04-09
Un elévè pose la question :
1. Les dimensions d'un rectangle sont a et b Si on augmente a de 3cm et b de 2cm, l'aire du rectangle augmente de 37 cm2, mais si on diminue a de 2cm et b de 1cm, l'aire du rectangle diminue de 16cm2. Quelles sont les valeurs de a et b?

2. Quelle est la valeur numerique de l'expression (ac+bd)+(ad-bc) sachant que a+b=1 et que c+d=1? Quelles sont les regles essentielles qui me manquent pour resoudre ceci?


Claude Tardif lui répond.
Septante 1999-12-18
Guillaume Bessis pose la question :
Pourqoui et depuis quand en France emploie-t-on l'expression 'soixante-dix' et non septante pour désigner 70 ? (idem pour 90 et nonante)
Claude Tardif lui répond.
A barrel on its side 2008-11-13
Dave pose la question :
Question from Dave:

How many gallons are left in a 36x60 in. barrel (laying on its side) and has 16 in. of gasoline left. I have attached a diagram.

Harley Weston lui répond.
The dimensions of a rectangle 2021-09-09
Ash pose la question :
I need to know how to figure out the dimensions of a rectangle. I know that the area is 30ft and the perimeter is 26ft. I'm 15 and I have no idea what I'm supposed to do.
Harley Weston lui répond.
3.1 miles in 4 minutes 2021-06-21
Jean pose la question :
I am a school bus driver. My route directions and time schedule have me traveling 3.1 miles in 4 minutes. How fast do "they" expect me to drive to accomplish this? Thank You
Penny Nom lui répond.
Time, distance and rate 2021-03-10
Zander pose la question :
A lady drives 180km from her wine farm to Ceres. On her return (at night) she drove 30km/h slower. Her return takes one hour longer. At what speed did she drive home?
Penny Nom lui répond.
Bearing and distance 2021-02-22
bahlqees pose la question :
A girl starts from a point X and walks 220m on a bearing 063°.she then walks to a point Y on a bearing 156°.if Y is due east of X,calculate|XY| solve and draw the diagram please
Harley Weston lui répond.
The dimensions of a rectangle 2020-11-02
Chie pose la question :
A rectangular piece of property has an area of 987m² and a perimeter of 136m. Find its LENGTH and WIDTH.
Penny Nom lui répond.
Running around a circular track 2020-10-31
kaylee pose la question :
Keiko and Kendra are training for an international track competition. Kendra is running one lap on the outside of a circular track with a diameter of 1000 feet. Her constant rate of speed is 12 mi/h. Keiko is running one lap on the outside of a nearby circular track with a diameter of 1125 feet. She is also running at 12 mi/h. Find the time, in minutes, each runner needs to complete one lap.
Harley Weston lui répond.
Two equations with fractions 2020-10-22
mia pose la question :
I am supposed to look for x and y. my teacher didn't explain very well.
please help : ((
2x - y = 5
x/4 + y/3= 2

Penny Nom lui répond.
A problem involving distance, time, and rate. 2020-09-15
Ruby pose la question :
Amy drove on the highways at 70 miles/hour to pick up fruits from her grandma’s garden in the morning.
She stayed there for two hours. When coming back in the afternoon, she drove on the local roads at 40 miles per hour to avoid traffic.
She spent a total of 8 hours for this trip, and drove a total 300 miles.
How many miles did she drive each way?

Penny Nom lui répond.
Simultaneous equations 2020-09-05
Paa pose la question :
a+b=8
a+c=13
b+d=8
c-d=6
find the value of each letter

Penny Nom lui répond.
A word problem with no algebra 2020-08-11
Julie pose la question :
At 3pm, Bruce headed north at 30 km/hr. 2 hours later, Lucy headed south at 40 km/hr. At what time will they be 340 km apart
Penny Nom lui répond.
A tank, 5/9 full of water 2020-07-28
Nat pose la question :
A rectangular tank contains 1200cmsquare of water when it is 5 out of 9 full . Its base area is 80cmsquare . Find the height of the tank.
Penny Nom lui répond.
Running in opposite directions around a circular track 2020-05-11
Alessandra pose la question :
2. Alan and Brian are two runners. Alan runs at 6.6 m/s and Brian runs at 8.4 m/s. They start from the same place on a circular 400 m track and run in opposite directions round and round the track.
(a) How far has Brian run when they pass each other for the first time?
(b) After they pass each other for the second time, how much further does Brian need to run in order to complete two laps (800 m)?

Penny Nom lui répond.
A system of equations. 2020-04-27
solomon pose la question :
xy + x =28
x + y +4

Penny Nom lui répond.
The width of a rectangle of land 2020-04-26
Teresa pose la question :
If a rectangle shape piece of land is 813 feet long. How many feet width would be 2 acres?
Penny Nom lui répond.
Why is a square a rectangle but a rectangle is not a square? 2020-04-15
A parent pose la question :
Why is a square a rectangle but a rectangle is not a square? Explain your answer.
Penny Nom lui répond.
A rectangular garde 2020-04-10
Denise pose la question :
In a rectangular garden a person says "if I made that bed 2 feet wider and 3 feet longer it Would have been 64 sq,ft bigger. But if it had been 3 feet wider and two feet longer It would have been 68 sq.ft bigger.
What is the length and width of the garden bed?

Penny Nom lui répond.
Sam and Claudia go on a bike hike 2020-03-03
Christie pose la question :
Sam and Claudia start at the same time on a bike hike of 150 miles. Sam travels 3 miles per hour faster than Claudia and finishes the trip 8 1/3 hours before Claudia. At what rate in miles per hour does Sam travel?
Penny Nom lui répond.
Filling a 48 cubic meter tank 2020-01-19
kamohelo pose la question :
An empty tank for storing water from a borehole has a volume of 480m3 if it is filled by a pump that pump water at a rate of 16L/s how many hours will it take the pump to fill this tank
Penny Nom lui répond.
A circle, a point, and a tangent line 2019-12-31
Faisal pose la question :
A circle has radius 10 units and passes through the point (5,-16). The x-axis is a tangent to the circle. Find the possible equations of circle?
Penny Nom lui répond.
The length and width of 1 1/3 acres 2019-11-22
Ben pose la question :
I’m trading to figure out what the length and width of 1 1/3 of an acre would be in a rectangle or in a perfect square
Penny Nom lui répond.
How do you find the length and the width if all you had was area? 2019-10-16
Ali pose la question :
So, How do you find the length and the width if all you had was area?
Penny Nom lui répond.
Simultaneous equations 2019-10-16
deepak pose la question :
This is too complicated please help me
8/x - 10/y = 1 and x+y=9

Penny Nom lui répond.
Mandy walks to work 2019-09-15
Kenneth pose la question :
Mandy walks to work at a constant rate. One-third of the way to work, she passes a bank. Three-fourths of the way to work, she passes a book store. At the bank her watch reads 7:52 A.M., and at the book store it reads 8:02 A.M. At what time is Mandy one-half of the way to work?
Harley Weston lui répond.
Distance traveled 2019-07-03
J pose la question :
If a fly flies at 15 feet per a second between two walls closing in upon themselves. Wall A is moving to the right at 3 feet a second and wall B is moving to the left at 15 feet a minute, how far will the fly fly before the walls touch?
Penny Nom lui répond.
A car drives over a cliff 2019-06-06
Victor pose la question :
A car was going 90 mph towards 90foot drop. What would the distance would the car travel horizontally ,from the cliff edge?
Penny Nom lui répond.
A dot on a child's car wheel 2019-04-28
julia pose la question :
A wheel of a child’s car revolves at 10 rpm. A painted dot on the circumference of the wheel is 12 cm from the centre of rotation of the wheel. How far does the dot travel in 5 s, to one decimal place?
Penny Nom lui répond.
Is every rectangle a rhombus? 2019-04-25
Danny pose la question :
Is a rectangle a rhombus??? True or False
Penny Nom lui répond.
Running around a circular track in opposite directions 2019-02-24
carmi pose la question :
how many times will lita and rose pass each other in 15 minutes if lita and rose start jogging on a 110 meters circular track. they begin at the same point but in opposite direction. lita at 8/3 meters per second and rose at 7/3 meters per second.
Penny Nom lui répond.
y=lnx+(1+ln2)/2 and y=x^2 2019-01-28
Mike pose la question :
Prove that y=lnx+(1+ln2)/2 and y=x^2 touch each other.

The course is about logarithm and root functions... how should I solve this problem?

Penny Nom lui répond.
A rectangle problem 2019-01-01
ahamed pose la question :
In rectangle ABCD, angle BCD is trisected. CE,CF meet the sides AB,AD at E,F. BE=6cm, AF=2cm so, find the area of the rectangle ABCD?
Penny Nom lui répond.
Simultaneous equations with fractions 2018-12-14
zaheer pose la question :
solve simultaneous equations and give answer in fractional form
3x - 2 = 4y +5/3
y + 7 = 2x + 4
would really appreciate some help on this please

Penny Nom lui répond.
Amy and Joey on a circular track 2018-08-13
Zoe pose la question :
Amy and Joey are situated on a circular track 400 feet around.
Joey starts running at a rate of 10 feet per second.
Amy waits for a full minute, then starts running from the same point (in the same direction) at 12 feet per second.

How many seconds elapse before Amy passes Joey on the track?

Penny Nom lui répond.
A tangent to a circle 2018-06-10
Bellle pose la question :
Determine the equation of the circle which has its center at (3,1) and tangent 3x-4y+5=0
Penny Nom lui répond.
Subdividing a rectangle into squares 2018-05-13
jeverzyck pose la question :
A rectangular board is 108cm wide and 156 cm long Equal squares as large as possible are ruled off this board.Find the size of the square.How many squares are there?
Penny Nom lui répond.
Two expressions for the perimeter of a a rectangle 2018-05-13
Slayde pose la question :
A rectangular house has one side 4 metres longer than the other. Create two different expressions for its perimeter. The expressions should be given in factorised and expanded form.
Penny Nom lui répond.
An egg falls from rest 2018-05-10
Amy pose la question :
An egg falls from rest a distance of 75cm to the floor. Neglecting air resistance, at what speed does it hit the floor?
Penny Nom lui répond.
Throwing a football 2018-04-26
Abby pose la question :
Daring Danny's threw a football at an angle of 40 degrees to the horizontal. The football hit the ground at 36 feet. Danny is 5 feet 1 inch tall. Find the initial velocity

I have been trying to figure this problem out for forever! Please help! I am really confused because I don't know time either and you are supposed to find that as well as velocity.

Penny Nom lui répond.
A rectangular prism with rounded corners 2018-04-25
Jackie pose la question :
Rectangular prism that is 40 by 20 with rounded corners with a radius of 2.5.

What would the surface area be?

Penny Nom lui répond.
Seven tangent circles 2018-04-23
Domenick pose la question :
How to calculate the circumscribed and inscribed circles formed by seven .019685 diameter circles arranged in a circle with all seven circles tangent to each other?
Penny Nom lui répond.
The distance between two men 2018-04-21
Kristin pose la question :
If a 5 ft 6 in man gets hit at a downward 45 degree angle by a 5 ft 10 in man, how far apart are the two men? AND, would the shorter man have to be kneeling or standing? Is there a formula and answer for this question?
Penny Nom lui répond.
A penny is thrown from the top of a building 2018-03-16
Zoraida pose la question :
A penny is thrown from the top of a 26.7-meter building and hits the ground 3.39 seconds after it was thrown. The penny reached its maximum height above the ground 0.89 seconds after it was thrown.

a. Define a quadratic function, h, that expresses the height of the penny above the ground (measured in meters) as a function of the number of seconds elapsed since the penny was thrown, t. b. What is the maximum height of the penny above the ground?

Penny Nom lui répond.
The dimensions of a rectangle 2018-03-03
Mia pose la question :
A wire of length 36cm is bent to form a rectangle. Find the dimensions of the rectangle.
Penny Nom lui répond.
Is a rectangle a parallelogram? 2018-02-28
ellie pose la question :
is a rectangle a parallelogram?
Penny Nom lui répond.
A cyclist reduces his speed 2018-02-27
Katherine pose la question :
Suppose the winner had reduced his average cycling rate by .1 mile per hour. By how much would his time have changed?

(the cyclist's rate is 23.66 miles per hour and the answer to the question before this one was that he cycled 2,292 miles in 96.87 hours)

Penny Nom lui répond.
A parallelogram, a rhombus and a rectangle 2018-02-07
Sambo pose la question :
what do parallelogram, rhombus and rectangle have in common?
Penny Nom lui répond.
Similar rectangles 2018-01-31
Kathy pose la question :
A rectangular picture frame is 14 inches long and 4 inches wide. Which dimensions could a similar picture frame have.
8 L X 21 W
35 L X 15 W
49 L X 14 W
7 L X 3 W

Penny Nom lui répond.
A tangent to a curve 2017-10-22
Jasem pose la question :

Suppose that
f(x)=(3x-3)^1/2.

(A) Find an equation for the tangent line to the graph of f(x) at x=2

(B) Find all values of xx where the tangent line is horizontal, and enter them as a comma-separated list (e.g., 2,-3,6). If there are none, enter none.

Values of x


Penny Nom lui répond.
Walking up and down a hill 2017-09-19
Justina pose la question :
At 2:20 p.m. Jack is at the top of the hill and starts walking down at the exact same time that Jill, who is at the bottom of the hill, starts walking up. If they maintain the uphill speed of 2mph and downhill speed of 4mph and the distance from the bottom to the top of the hill is 1.5 mi, at what time will Jack and Jill meet?
Penny Nom lui répond.
Up a hill and down again 2017-09-17
justina pose la question :
Jack and Jill travel up a hill at a speed of 2mi/h.they travel back down the hill at a speed of 4mi/h.what is their average speed for the entire trip? express your answer as a mixed number
Penny Nom lui répond.
Simultaneous equations with fractions 2017-09-09
Farah pose la question :
Hi, my name is Farah. I hope you can help me with this question . X/2 + g/5= 3 and 2g - f = 10
Penny Nom lui répond.
The volume of an attic 2017-09-07
paul pose la question :
trying to determine volume of an attic base is rectangular 29 ft by 37 ft peak runs parallel to longest base side and is 7 ft long roof lines run from each end of the peak to the respective corners the peak is 3.5 ft above the base
(so seen from above there are 5 visible lines: the peak and 1 line to each of the 4 corners)

Harley lui répond.
Simultaneous equations 2017-09-02
keto pose la question :
x-y=2,x^2+xy=12
Penny Nom lui répond.
A car on a rough road and a concrete road 2017-08-27
Ken pose la question :
A car is driven on a rough road at a speed of 25km and then on a concrete road with a speed of 70kph. The car has 5.5 hours to travel 225km. How long did the car travel on concrete road?
Penny Nom lui répond.
A rectangle and a circle 2017-08-12
Ramzan pose la question :
a diagram shows the shape of rectangular framework with length (2x+20)cm and with (y+10)cm . The outline is made of wire . If a circle with diameter 56 cm is to be made from the wire and the area of the rectangle is 420 square centimeter ,find the possible lengths and width of the rectangle
Penny Nom lui répond.
A police officer spots a speeding car 2017-07-20
Josh pose la question :
Marie, a police officer, spots a speeding car and starts chasing it. The speeding car travels at a speed of 130 feet per second. Marie's car reaches a constant speed of 145 feet per second 1725 feet from the start of the chase. During that time, the speeding car has traveled 3150 feet. Write a system of equations to represent this situation.
Penny Nom lui répond.
Squares and rectangles 2017-07-15
Tront pose la question :
So, there's a general rule that all squares are rectangles but not all rectangles are squares. Im trying to find a term that would describe this relationship. I've found that if all of A is B but not all B is A then I'd say that A is a subset of B, but is there a term that describes the relationship as a whole? I don't want to describe the components, I want to describe the relationship as a whole.
Penny Nom lui répond.
How fast am I travelling? 2017-06-24
corey pose la question :
if i travel 2 miles in 10 seconds, how fast am i travelling please
Penny Nom lui répond.
A man drives 48km in 45 minutes 2017-06-03
Jamal pose la question :
A man drives from Ibadan to Oyo a distance of 48km in 45 minutes. If he drives at 72km/h where the surface is good and 48km/h where the surface is bad. Find the number of kilometers of good surfaces
Penny Nom lui répond.
Simultaneous equations with fractions 2017-06-02
Jamal pose la question :
1/x + 1/y =5 and 1/y - 1/x =-1
Penny Nom lui répond.
The maximum area of a rectangle with a given perimeter 2017-06-02
Bob pose la question :
How would I go about finding the maximum area of a rectangle given its perimeter (20m, for example)?
Penny Nom lui répond.
A cylindrical water tank with a leak 2017-06-01
Alexander pose la question :
if a cylindrical water tank has diameter of 90cm and leak starts at the bottom 10 litres in an hour. how long will it take for the level to fall by 20cm
Penny Nom lui répond.
Initial velocity 2017-05-23
Annelle pose la question :
a body is thrown vertically downward from a height above the ground. determine the initial velocity and the height of the starting point if after 4 secs it reaches the ground with velocity of 68 m/s.
Penny Nom lui répond.
The length of a train 2017-04-24
Stefano pose la question :
If a freight train is coming towards you and you were traveling at 85 miles an hour and it takes 35 seconds for the train to pass you how long is the train

Figure 50mph for train

Penny Nom lui répond.
Quadratic Equations 2017-03-28
Natalie pose la question :

Hi Maths Central,

I am having trouble with quadratic equations. The question is:

Calculate the length 'l' of a rectangular pool by creating and solving a quadratic equation.

1. The rectangular pool is of equal area to a square pool, and a circular pool (5.70m^2).
2. The length of the rectangular pool must be 2m longer than the width 'w'.

Thank you so, so much for your help, Maths Central!


Penny Nom lui répond.
A block base for a plywood rectangle 2017-02-18
Joe pose la question :
How many cinder blocks 16x8 would i need to build a solid base for a plywood base 54inches wide and 30 inches deep Thank you
Penny Nom lui répond.
Five equations 2017-01-16
Muhammed pose la question :
A x 4 = E
B ÷ 4 = E
C + 4 = E
D - 4 = E
___________
& A + B + C + D = 100
what is the value of E

Penny Nom lui répond.
A rectangle with a given perimeter and area 2017-01-11
Joe pose la question :
i have a math question for homework that i don't understand. can you draw a rectangle that has 18cm in perimeters and 20cm in areas. i tried but i can't.
Penny Nom lui répond.
Simultaneous equations with fractions 2016-12-21
Kimi pose la question :
I am stuck on this,can someone please help me????

1/2x+1/3y=11
8x+2/5y=102
Can someone please explain how to solve questions like these?? Or else I will never learn...
Thank you

Penny Nom lui répond.
The area of a city block 2016-12-08
Miura pose la question :
A city block is three times as long as long as it is wide.if the distance around the block is 0.48 kilometers, what is the area of the block in square meters?
Penny Nom lui répond.
Is every rectangle a rhombus? 2016-11-28
Robert pose la question :
not every rectangle is a rhombus.true or false? if false please leave a short explanation. thank you:)
Penny Nom lui répond.
Two tangent circles 2016-11-27
mikee pose la question :
find the equation of a circle tangent to the circle x2­+y2=4 and with the center at (0,5)
Penny Nom lui répond.
Simultaneous equations 2016-11-25
Rohan pose la question :
x-2/3 + y - 1/4 = 13/12
2-x/2 + 3 + y/3 = 11/6

Penny Nom lui répond.
The area of a rectangle 2016-11-05
Ivan pose la question :
If the vertices of a rectangle are a(1,3),b(3,-4),and c(1,-4),find it area.
Penny Nom lui répond.
Travelling upstream and downstream 2016-10-17
Kathleen pose la question :
It took a boat 2 hours to reach town A going upstream. The way back was 1h20 min. What is the speed of the boat in still water if the speed of the stream is 3 mph?
Penny Nom lui répond.
A 2 million gallon tank 2016-09-28
Kimberly pose la question :
I have a tank that is shaped like a cylinder, and it has to hold 2 million gallons of water. There is a height limit of 30 ft. I know the equation is V=pi x r squared x h but I don't know if I need anything For the square foot of water.
Penny Nom lui répond.
A car chase 2016-09-25
Ms. pose la question :
Car 1 is traveling down the road at 50 mph and passes Car 2 is sitting on the side of the road. Car 2 needs to catch Car 1 one half mile down the road. How fast must Car 2 drive to catch Car 1 if Car 2 waits 10 seconds before pursuing Car 1?

Yes, the assumption is that the Car 2 can accelerate from a standing position and over take Car 1 rate. What is the answer or formula for this type of question?
Respectfully
Befuddled Mom?

Penny Nom lui répond.
How fast and how far must Car 2 travel before catching Car 1? 2016-09-25
Ms. pose la question :
Car 1 is traveling down the road at 50 mph and passes Car 2 is sitting on the side of the road. Car 2 needs to catch Car 1 one half mile down the road. How fast must Car 2 drive to catch Car 1 if Car 2 waits 10 seconds before pursuing Car 1?

Yes, the assumption is that the Car 2 can accelerate from a standing position and over take Car 1 rate. What is the answer or formula for this type of question?
Respectfully
Befuddled Mom?

Penny Nom lui répond.
Standard form 2016-09-22
anna pose la question :
ok. i have b=2/3x+5/7. im supposed to change it to standard form. how do i do that?
Penny Nom lui répond.
The width of a 300 foot long rectangular acre 2016-09-21
Debbie pose la question :
If 2 sides of a 1 acre plot is 300 feet each what are the other 2 sides? The acre is a rectangle.
Penny Nom lui répond.
The distance around a warehouse 2016-09-21
Chuck pose la question :
How far do I walk when I walk around a 751,000 sq. ft. warehouse?
Penny Nom lui répond.
The dimensions of a rectangle 2016-08-31
Hazym pose la question :
How do I find the length(which is 15m longer than the breadth) and the breadth of a rectangle just by its perimeter which is 70 m?
Penny Nom lui répond.
The dimensions of a rectangle 2016-07-25
Krunox pose la question :
A rectangle is twice as long as it is wide. Its perimeter (the sum of the lengths of its sides) is 60 cm. Find its length and width.
Penny Nom lui répond.
Two equations with fractions 2016-07-22
kanesh pose la question :
p/2+q/3=3

p/4+2q/3=3

Penny Nom lui répond.
Simultaneous equations 2016-06-25
sena pose la question :
2x/3+3y/2=-1
4x-5y=22

simultaneous equation

Penny Nom lui répond.
The difference between the ares of two rectangles 2016-06-09
Ingrid pose la question :
I am trying to help my son with an area question.
I have the answer, from the solutions, but I cannot figure out how to teach him.

Question:

Two rectangles have lengths 13cm and 19cm respectively.
Their total area is 376cm squared.
If both their widths are whole numbers, what is the difference in their areas?

I know that this is solvable once I determine the widths of the rectangles ,
but how do I go about finding that?

Thanks for your help

Chris Fisher and Harley Weston lui répond.
John and Max walk to meet each other 2016-05-29
abhay pose la question :
The speeds of John and Max are 30 km/h and 40 km/h.Initially Max is at a place L and John is at a place M. The distance between L and M is 650 km. John started his journey 3 hours earlier than Max to meet each other. If they meet each other at a place P somewhere between L and M, then the distance between P and M is?
Penny Nom lui répond.
The volume of a truncated rectangular pyramidal pond 2016-05-13
Paul pose la question :
How do you calculate a partially filled truncated rectangular pyramid if you always know the bottom rectangle, the maximum height top rectangle perimeter, but have a varying height. Similar to filling up a pond you know the current height and dimensions at the max rectangle how do you calculate it half full i.e. 10x30 outside perimeter with a 2x8 base and a max height of 6ft how do you calculate it at 3ft without re-measuring the top perimeter. Thanks, Paul
Harley Weston lui répond.
A pair of equations with fractions 2016-05-11
tiya pose la question :
hello, i want to know how to solve this question.

m/6+2n/3=6
-m/10=2n/5=2

Penny Nom lui répond.
At what time will Sara catch up with Jake? 2016-05-07
Laura pose la question :
At 11:00 a.m., Jake started driving along a highway at constant speed of 50 miles per hour. A quarter of an hour later, Sara started driving along the same highway in the same direction as Jake at the constant speed of 65 miles per hour. At what time will Sara catch up with Jake?
Penny Nom lui répond.
A rectangular field 2016-05-07
Jan pose la question :
A rectangular field is 63m long and 21m wide. A fence of 2m in height is needed to fence the field and fencing is also required to divide the field in three square sections. There are three wooden gates measuring at 1.5m to the three sections of the field. What is the total surface area of the fence needed for fencing and diving the field?
Penny Nom lui répond.
A 3 hour river cruise 2016-05-06
Jan pose la question :
A 3 hour river cruise goes 15km upstream and then back again.The river has a current speed of 2km/h.what is the boat's speed and how long was the upstream journey?
Penny Nom lui répond.
15.86 acres 2016-04-21
Ronald pose la question :
If a rectangular piece of land is 1320 ft. on one side, how many feet would be required on the other side to equal 15.86 acres?
Penny Nom lui répond.
The area and the perimeter of a rectangle 2016-04-12
kimberly pose la question :
is there a relationship between the are and the perimeter of a rectangle? explain.
Penny Nom lui répond.
tan15° 2016-04-11
JOHN pose la question :
find the exact value of tan15° in surd form.
Penny Nom lui répond.
A road trip word problem 2016-04-10
Marc pose la question :
While on a road trip I imagined this random word problem. Suppose I start a trip of 75 miles. My initial speed is 75 miles per hour. After every mile traveled I decrease my speed by one mile per hour. After the first mile I decrease my speed to 74 miles per hour and so on for each subsequent mile traveled. How long will it take to complete the 75 mile journey?
Penny Nom lui répond.
A tilted cylinder tank 2016-03-28
Astri pose la question :
I have a problem determining the fluid level for tilted cylinder tank. Actually I've found some solution here for horizontal cylinder tank. What if the cylinder is tilted at a certain degree, for example 30 degree from the vertical axis.
Thank you.

Penny Nom lui répond.
Biking and jogging 2016-03-17
alondra pose la question :
Ricky went on a bike ride. After 6 miles he got a flat tire and had to jog home. He jogs 3mph slower than he bikes, so the jog took 1 hour longer than the bike ride. At what rate did he travel each way?
Penny Nom lui répond.
The perimeter of a rectangle 2016-03-17
Linda pose la question :
Noel correctly adds the length of three sides of a rectangle and gets 88 cm her brother Ryan correctly adds the lengths of three sides of the same rectangle and gets 80cm. What is the number of cm in the perimeter of the rectangle
Penny Nom lui répond.
tan inverse 1/4 2016-03-14
nazz pose la question :
prove; tan inverse 1/4=1/3 cot inverse 52/47
Chris Fisher lui répond.
The area of a rectangle 2016-03-03
Lucas pose la question :
The area of a rectangle is given by A=x2+18x+72
-use factoring to find an expression for the dimensions of the rectangle.
-if the area of the rectangle is 7 square feet, what are the possible values of x?
-what are the dimensions of a rectangle?

Penny Nom lui répond.
A rectangular prism 2016-03-02
Paula pose la question :
Trying to help with a math problem. I don't know how to set up the equation for this.

A rectangular prism has a volume of 7.875m3rd and a height of 3.5 m. What is the area of the base of the prism?

Thanks for your help!

Penny Nom lui répond.
Solve for x and y 2016-02-27
ntshidi pose la question :
Y=1/2x+4and1/4x-6
Penny Nom lui répond.
Two equations in two unknowns 2016-02-13
Anumba pose la question :
4x + 2y = 4
7x - y = -11

Penny Nom lui répond.
Travelling with and against he current 2016-02-09
Lloyd pose la question :
A boat travelled 210 miles downstream and back. The trip downstream took 10hrs, the trip back took 70hrs
1. what is the speed of the current?
2. what is the speed of the boat in still water?

Penny Nom lui répond.
A two car competition 2016-02-02
Christian pose la question :
Question: Two cars are racing to a fixed point and back. One car travels 70 MPH both ways While the other travels 60 MPH there and 80 MPH back, which car won the race? It is not a tie.
Penny Nom lui répond.
A system of linear equations 2016-01-24
kareem pose la question :
my name is kareem
and i am a student i have a math puzzle and i tried to solved it but it always have same mistake
x-y=9
x+z=12
z-n=14
y+n=2

Penny Nom lui répond.
Complex numbers in standard form 2016-01-15
Michael pose la question :
express the following complex numbers in standard form (2+3i)+(5-2i)
Penny Nom lui répond.
A rectangular enclosure 2016-01-15
Amber pose la question :
A rancher wants to use 300ft of fencing to enclose a rectangular area of 4400 square feet. What dimensions should the rectangle be?
Penny Nom lui répond.
Water flowing through a rectangular drain 2016-01-08
Tiffany pose la question :
the cross section of drain is a rectangle 30 cm wide. If water 3.5 cm deep flows through the drain at a rate of 22 cm/s, how many litres of water will flow through in one minute?
Penny Nom lui répond.
The area of a rectangle 2016-01-08
ranjan pose la question :
if we make a rectangle with a 100cm of wire, then its area will be?
Penny Nom lui répond.
A circle is inscribed in a hexagon 2015-12-28
Lalitesh pose la question :
A circle is inscribed in a regular hexagon ABCDEF
Prove that AB+CD+EF=BC+DE+FA

Penny Nom lui répond.
Constructing simultaneous linear equations 2015-12-28
Deborah pose la question :
Linda thinks of a two-digit number. The sum of the digits is 8. If she reverses the digits, the new number is 36 greater than her original number. What was Linda's original number?

Thank you!

Penny Nom lui répond.
Linear equations in two variables 2015-12-13
priya pose la question :
I have problem in solving these equations please help me today itself very urgent:
I)2x+y=y
II)pie*x+y=9

Penny Nom lui répond.
The dimensions of a rectangle given its area and aspect ratio 2015-12-13
colum pose la question :
Can you work out the length and width of a rectangle where you know only the area and aspect ratio
Penny Nom lui répond.
Matthew skateboards around the school 2015-12-09
Abigail pose la question :
Matthew skateboards 4km each hour.
How long will it take him to skateboard around the school yard measuring 300m by 200m.? Thank you.

Penny Nom lui répond.
Travelling in opposite directions 2015-12-06
Roselyn pose la question :
Jenny and Mark commute to work, travelling in opposite directions. Jenny leaves the house at 8 AM, and averages 35 kph. Mark leaves at 8:15 AM, and averages 40 kph.At what time will they be 40 kilometers apart?
Penny Nom lui répond.
A tangent line to a parabola 2015-12-02
pei pose la question :
Given that the line y=mx-5 is a tangent to the curve y=2x^2+3 find the positive value of M.
Penny Nom lui répond.
Riding a mountain bike up and down a mountain 2015-12-02
sam pose la question :
Michael, can climb a mountain at 2.5km/hr on his mountain bike. he descends the mountain at 5.5km/hr. he completes the whole circuit in 7 hours. how long is the trail to the top of the mountain?
Penny Nom lui répond.
A common tangent to two general parabolas 2015-11-15
Kind pose la question :
Hi, I want to find the common tangent of two general parabolas, but i don't know if it's possible or not.
If it's possible, please make a tutorial.

The first parabola equation : Ax^2 + Bxy + Cy^2 + Dx + Ey + F = 0.
The second parabola equation : Gx^2 + Hxy + Iy^2 + Jx + Ky + L = 0.

I need this because i want to find the equation of Beloch fold. (Huzita - Hatori 6th axiom) However if you know any other method to find Beloch folds equation, I am open for any suggestions.

Chris Fisher lui répond.
Fencing around a rectangular field 2015-11-11
Darlene pose la question :
Question from Darlene, a parent: A farmer has 10,000 meters of fencing to use to create a rectangular field. He plans on using some of the fencing to divide the rectangular field into two plots of land by constructing a fence inside the rectangle that is parallel to one of the sides. Let X be the width of the rectangular field. Write an equation to express the area of the field as a function of X. Find the value of X that maximizes the area of the field.
Penny Nom lui répond.
The length of a rectangle 2015-09-26
Tris pose la question :
Hi,
I'm trying to figure out the length of a rectangle but i forgot how. So, the width is 5cm and the perimeter is 34cm.

Penny Nom lui répond.
The dimensions of a rectangle 2015-09-25
Erick pose la question :
A rectangular strip of land has a perimeter of 124meters and an area of 385 square meters. Find its possible dimensions
Penny Nom lui répond.
A tangent line to a circle 2015-09-03
Jamie pose la question :
Use the Greek method to find an equation of the tangent line to the circle x^2+y^2-4x+6y+4=0 at the points (3,2square root 2-3.
Penny Nom lui répond.
The distance between two boats 2015-07-26
mohammad pose la question :
Two boats leave the same dock at the same time,one traveling due east at 10 mph and the other due north at 24mph,how many miles apart are the boats after 3hours ?
Penny Nom lui répond.
A waste oil tank 2015-06-13
Angela pose la question :
a waste oil tank is 5 feet wide and 20 feet long, the empty tank on your truck holds 5000 gallons. If 7.48 gallons are in every cubic foot, what is the maximum depth the oil can be to completely fit into your truck?
Penny Nom lui répond.
A tangent to y = x^3 2015-05-31
Brayden pose la question :
Show that a tangent line drawn to the curve y=x^3 at the point (d,f (d)), where d>0, forms a right triangle with the x and y axes in quadrant 4 whose area is (2/3)d^4.
Penny Nom lui répond.
The perimeter of a rectangle 2015-05-28
Imran pose la question :
The length of a rectangle is x+3 centimetres.
The width of the rectangle is x-1 centimetres.

Find an expression in terms of x for the perimeter of the rectangle.
The perimeter of a rectangle The perimeter of a rectangle
Give your expressions in it's simplest form.
The perimeter of a rectangle The perimeter of a rectangle
Thank You.

Penny Nom lui répond.
Two lorries approaching an intersection 2015-05-15
Nuraini pose la question :
Two straight roads intersect at the right angles. Lorry A, moving on one of the roads, Approaches the intersection at 50mi/h and lorry B, moving on the other roads, approaches the intersection at 20mi/h. At what rate is the distance between the lorry changing when A is 0.4 mile from the intersection and B is 0.3 mile from the intersection?
Penny Nom lui répond.
Folding a rectangle to preserve the aspect ratio 2015-05-09
Anna pose la question :
If you fold a rectangular piece of paper in half and the resulting rectangles have the same aspect ratio as the original rectangle, then what is the aspect ratio of the rectangles?
Penny Nom lui répond.
A circle is tangent to the y-axis 2015-05-06
Elynna pose la question :
What does it mean when a circle is tangent to the y-axis?

Thanks,

Penny Nom lui répond.
The method of elimination 2015-05-01
oreanna pose la question :

Question from oreanna, a student:

How do u solve 2x+9y=3

7x-4y=-25 in elimination


Penny Nom lui répond.
A square and a rectangle 2015-05-01
nick pose la question :
why is the area of a square of a given circumference greater than the area of a rectangle with the same circumference ?
Penny Nom lui répond.
Two concentric circles 2015-04-21
Juniper pose la question :
Two concentric circles have radii of 4 cm and 8 cm. A segment is drawn so that it is tangent to the smaller circle and a chord of the larger circle. How long is the segment?
Penny Nom lui répond.
Two cars approaching an intersection 2015-04-16
Engabu pose la question :
Car A is traveling west at 50km/h & car B is traveling north at 60km/h. both are headed for the intersection of the two roads. At what rate are the cars approaching each other when car A is 3km & car B is 4km from the intersection?
Penny Nom lui répond.
Two airplanes 2015-04-14
john pose la question :
two planes leave an airport at the same time, one going northwest (N35*W)at 400 mph and the other going east at 332 mph. How far apart are the planes after 4 hours to the nearest mile?
Penny Nom lui répond.
A word problem with fractions 2015-04-09
Lorraine pose la question :
If the numerator of a certain fraction is doubled and the denominator is increased by 1, the fraction becomes 1/2.

If the numerator of the original faction is squared and the denominator is decreased by 2, the fraction becomes equal to 1.

Let x be the numerator and let y be the denominator of the original fraction. Write down two simultaneous equation in x and y.

Solve these equations to find two possible values for the given fraction.

Penny Nom lui répond.
A tangent to y=x^3 passes through (0,2) 2015-04-05
Kevin pose la question :
Given that the curve y=x^3 has a tangent line that passes through point (0,2). Find the equation of the tangent line
Penny Nom lui répond.
A rectangular concrete tank 2015-03-24
mwenge pose la question :
What is the length ,width and height for the rectangular concrete tank that can have capacity of 50000 liters of water?
Penny Nom lui répond.
A train trip 2015-03-23
Ngcebo pose la question :
A train travels a distance of 720 km at a speed of x km/h. on the return journey, it travels at an average speed of y km/h and completes the whole journey in an hour less. if the speed during the return journey was 10 km/h more, what were the speeds in m/s
Penny Nom lui répond.
Average rate for a return trip 2015-03-14
Michael pose la question :
Jeffrey drove to a town 25 miles away at an average speed of 50 miles per hour. The return trip along the same route took 20 minutes longer than the trip to town. Determine the average speed in miles per hour for Jeffrey's round trip.
Penny Nom lui répond.
Two parallel tangents to a circle 2015-03-05
Samantha pose la question :
The equation of a circle is x^2+y^2=25. Determine the equation of the parallel tangent lines to this circle, for which the slope is 4/3.
Penny Nom lui répond.
Istanbul to Lagos 2015-03-03
Victor pose la question :
A plane flies from Istanbul to Lagos at 800km/h and then returns to Istanbul at 900km/h. The return trip takes 1 hour less than the flight to Lagos. What is the distance between Istanbul and Lagos?
Penny Nom lui répond.
Two equations with fractions 2015-02-26
Pulane pose la question :
Hi math centre I've been trying to solve these equations for days now please help (6/x)-(1/y)=4
(9/x)+1=(-2/y)

Please help me solve them simultaneously
Thank you

Penny Nom lui répond.
Two equations 2015-02-16
nigel pose la question :
2x+1/2y=1
6x-3/2y=21

Penny Nom lui répond.
Distance, time and rate for three people 2015-02-15
Mubashir pose la question :
Steven left Town A and walked towards Town B at a speed of 100m/min. At the same time, Jason and Melvin started from Town B and walked towards Town A at a speed of 80m/min and 75m/min respectively. If Steven met Melvin six minutes after passing Jason, find the distance between Town A and Town B.
Penny Nom lui répond.
Bearings and a rectangular plot 2015-02-14
Mubashir pose la question :
A,B,C,D are the four corners of a rectangular plot marked on level ground. Given that the bearing of B from A is 040 degrees and that the bearing of C from A is 090 degrees. Calculate the bearing of
(a)B from C
(b)A from C
(c) D from C

Penny Nom lui répond.
Stopping distance 2015-02-11
Audrey pose la question :
A Harley Davidson motor cycle weighing 650 lbs with a rider weighing 175 bs was going 40 miles per hour. He had to make a sudden stop . Slammed on brakes. How long a distance for him to stop?
Penny Nom lui répond.
A word problem with fractions 2015-02-11
Omokayode pose la question :
A vehicle tank was 3/5 full of petrol. When 21 litres of fuel was added it was 5/6 full. How many litres of petrol can the tank hold?
Penny Nom lui répond.
A circle and a chord 2015-02-07
Dakota pose la question :
If the diameter of a circle is 48 cm, find the shortest distance from a chord of length 34 cm to the center of the circle
Penny Nom lui répond.
Speed, distance and time 2015-02-06
Terry pose la question :
How many seconds would it take to travel 0.18 km at a speed of 130km per hour?
Penny Nom lui répond.
Two cars pass each other going in opposite directions 2015-02-03
Caroline pose la question :
Two cars pass each other going i opposite directions. One car is going 100 km/h and the other is going 80 km/h. How far apart will the two cars be after driving 45 minutes at these rates of speed?
Penny Nom lui répond.
A train from Vancouver to Whistler 2015-02-02
Tea pose la question :
Serena and Nina are taking a train from Vancouver to Whistler, a 160km trip. If the average speed is decreased by 16km/hr, the trip will be 1/2 hours longer. What is the average speed of the train? Thanks :)
Penny Nom lui répond.
A motorbike race 2015-01-25
Pramegh pose la question :
In a motorbike race of 75 km, the winner completes the race with a lead of 300 meters and 8 seconds before the second rider. Considering the riders ride with an average speed, find the difference between their speeds with which they completed the race.
(Calculate up to 2 decimal places)

Penny Nom lui répond.
Two cars 2015-01-18
taylor pose la question :
two cars leave the park at the same time, one traveling north at a speed 10 mph faster than the other which is traveling south. after 3 hours the cars are 420 miles apart. find the speed of both cars
Penny Nom lui répond.
The length of a roll of paper 2015-01-12
Peggy pose la question :
roll of paper 3ft wide and roll equals 500 sq ft how long would the roll be?
Penny Nom lui répond.
196 kilometer in2 hours 2014-12-29
Ekanem pose la question :
QQ A motorist had planned to reach a place 196km in two hrs exactly. For the first 15km he was able to average only 40km/h. What average speed must he keep up for the rest of the journey if he is to arrive on time.
Penny Nom lui répond.
A tangent to a circle 2014-12-22
azman pose la question :
Find the equation of the tangent line to the circle x^2+y^2=9 at the point P (2, square root of 5).
Penny Nom lui répond.
What is the speed of the boat in still water? 2014-10-30
Adam pose la question :
The current in a stream moves at a speed of 2 km/h. A boat travels 38 km upstream and 38 km downstream in a total time of 3 hr. What is the speed of the boat in still water?
Penny Nom lui répond.
A linear system 2014-10-14
pheter pose la question :
4/x - 1/y = 3 .... equation (1)
6/x - 2/y = 5 .... equation (2)

Penny Nom lui répond.
A rectangle and a triangle 2014-09-27
rajesh pose la question :
The perimeter of a rectangle is equal to the perimeter of a right-angled triangle of height 12 cm if the base of the triangle is equal to the breadth of the rectangle, what is the length of the rectangle?
Penny Nom lui répond.
A man a ship and a wharf 2014-09-26
Ralph pose la question :
A man om wharf 12 meters above the level of water is pulling a rope tide to a boat at the rate of 2 meters per minute. How fast is the boat approaching the wharf when there are 20 meters of the rope our. (with solution)
Penny Nom lui répond.
Two equations in x and y 2014-09-25
seyilogo pose la question :
solve y=2x - 3 and (4x - 2y) / x + y = 1 simultaneously
Harley Weston lui répond.
Two equations in two variables 2014-09-18
Susan pose la question :
(28x + 36y) - [20000 - .75(28x + 36y) + 60000] = 5000
x + y = 10000
solving two equations involving variables

Penny Nom lui répond.
A tangent to a curve passing through a point not on the graph 2014-09-15
Aquilah pose la question :
For the curve y = x2 + 3x, find the equations of all tangent lines for this graph that also go through the point (3, 14).
Penny Nom lui répond.
The perimeter and diagonal of a rectangle 2014-09-10
niniha pose la question :
the perimeter of a rectangle is 68cm.if the diagonal is 26, find its dimensions
Penny Nom lui répond.
Problem solving 2014-09-08
hubert pose la question :
a car left the house and travelled at an average speed of 60 kph.how many minutes will it take for the car to reach the school which is 8 km away from the house
Penny Nom lui répond.
A car passing a bus 2014-08-24
Athish pose la question :
the driver of the car is travelling at 36 km/hr and spots a bus 80 m ahead of him after 1 hr the bus is 120 m behind the car what is the speed of the bus
Penny Nom lui répond.
Distance, speed and time 2014-08-13
abdel pose la question :
Mac walked to a park from the college at 5 km/h. 10 minutes later, Steve started riding his bike at 15 km/h to the same park to meet Mac. They arrive at the same time at the park. How far is the park from the college?
Tyler Wood lui répond.
Speed, distance, time 2014-08-13
Aarti pose la question :
a theif running at 8 km/hr is chased by a policeman whose speed is 10km/hr.if the thief is 100 m ahead the policeman then what will b time required for the policeman to catch the thief?
Tyler Wood lui répond.
The dimensions of a rectangle 2014-08-03
Jamaica pose la question :
if the perimeter of a rectangle is 30m and its area is 56 m2.find its length and width?
Penny Nom lui répond.
The method of elimination 2014-07-05
leo pose la question :
please explain how can i solve this problem

3x-6y=-38
6x-9y=44

using elimination and simultaneous method thank you :)

Penny Nom lui répond.
The width of a rectangle 2014-07-02
john pose la question :
if the area of a rectangular field is 90 sq. m and its length its is 19 m find its width
Penny Nom lui répond.
Simultaneous equations 2014-06-20
rana pose la question :
solve the simultaneous equations
a)3x=7y
12y=5x-1

Penny Nom lui répond.
The number of standard deviations 2014-06-15
Dawn pose la question :
Suppose that, at a certain college, the average weight of all male students is 160 pounds with a standard deviation of 30 pounds. A certain male student weighs 145 pounds. Determine how many SD's his weight is above or below average.
Penny Nom lui répond.
A model of the sun and the Earth 2014-06-14
Lynn pose la question :
There is a model of the sun that is 2 1/2 inches in diameter. This is the only clue we have! How far away is the earth from this model?
Penny Nom lui répond.
What is the speed of the buses? 2014-05-18
musliu pose la question :
Two buses leave a bus station and travel in opposite direction from that same starting point.if the speed of one is twice the speed of the other and they are 240km apart at the end of 1h, what is the speed of the buses?
Penny Nom lui répond.
A circle a square and a rectngle 2014-05-12
mazhar pose la question :
suppose the length and breadth of the rectangle are 5 cm and 10 cm respectively and M is a point along the corner of the circle. what is the radius of the circle?(diagram is given..but i didn't mention it..actually the diagram looks like a circle inscribed in a square and the right bottom corner one rectangle will be given ,it is touches to circle at a point M that I've already mentioned and the dimensions of that rectangle also I've mentioned) please help me out..
Penny Nom lui répond.
Travelling upstream and downstream 2014-05-12
Mohanad pose la question :
Howie Sorkin can travel 8 miles upstream in the same time it takes him to go 12 miles downstream. His boat goes 15 mph in still water. What is the rate of the current?
Penny Nom lui répond.
2 cars driving towards each other 2014-04-27
Joakim pose la question :
2 cars driving towards eachother , the distance between them is 162km. they meet after 2 hours. car A is driving with 4/5 of car B´s speed. what is the speed of each car...
Penny Nom lui répond.
What time was it when joe's brother passed him? 2014-04-25
Nathan pose la question :
joe left home in his bike at 10:00 am, traveling 21 km/h. At noon, his brother set out after him on his motorcycle, following the same route. if the motorcycle traveled at 63 km/h, what time was it when joe's brother passed him?
Penny Nom lui répond.
Simultaneous equations with fractions 2014-04-19
Maryam pose la question :
I looked at your example of simultaneous equations with fractions and applied it to my question from an educate exam papers but I couldn't get it to work. The question is:

x/8 - y = -5/2
3x + y/3 = 13

Penny Nom lui répond.
A tangent of the curve (x/a)^n+(y/b)^n =2 2014-04-15
sudhir pose la question :
the equation of tangent of the curve (x/a)^n+(y/b)^n =2. at(a,b) is
Penny Nom lui répond.
Two rectangular prisms 2014-04-10
hannah pose la question :
two rectangular prisms have a combined volume of 432 cubic feet Prism A has half the volume prism b has what are the volumes of prism a and prism
Penny Nom lui répond.
Two circles that touch each other externally 2014-04-08
Ameya pose la question :
Two circles of radii a and b (a > b) touch each other externally. ST is a common tangent touching the circles at S and T respectively, then ST^2 is equal to
Chris Fisher lui répond.
The surface area of a rectangular prism 2014-04-08
Manraj pose la question :
Find the surface area of a rectangular prism with dimensions 4, 5, and 7 units.
Penny Nom lui répond.
A cubical tank 2014-04-01
renzo pose la question :
A cubical tank contains 2048 cubic ft of water when HALF-FULL. Find the total area of the tank and the length of its diagonal
Penny Nom lui répond.
A circle which is tangent to two perpendicular lines 2014-03-09
MJ pose la question :
I'm a College Student taking up Bachelor of Secondary Education on Math Subject. And I'm struggling for my research about Circles. I done solving the said topic particularly on this question:

"What are the possible equations of a circle being tangent to a pair of perpendicular lines, having the origin as the Point of Intersection and the C (h, k), where h, k ∈ℤ"

But I can't get what would be the process that I must do in order to jive to my idea/goal for that problem.
Please check my idea that the numerical coefficients of the equation is equal to the radius of the circle. Thanks in advance! :)

Penny Nom lui répond.
A speed word problem 2014-02-24
kiss pose la question :
Hank bicycles 5 km/h slower than Kelly. In the time that it takes Hank to bicycle 42 km, Kelly can bicycle 57 km. How fast does each bicyclist travel?
Penny Nom lui répond.
Simultaneous fractional equations 2014-02-15
benjamin pose la question :
hi math central. benjamin here. during class, i had problem with this topic. normally i wont have problems with math but this topic i just too hard for me. please help i am having exam and test next week on this topic

here is the question:
using substitution method, solve the simultaneous equation.
(x+1)/(y+2)=0.5

(x-2)/(y-1)=1/3

Penny Nom lui répond.
Two bicyclists traveled in opposite directions 2014-02-07
Susan pose la question :
Two bicyclists traveled in opposite directions, one at a rate of 8 km/hour and the other at a rate of 7 km per hour. In how many hours were they 45 km apart?
Penny Nom lui répond.
Walking up and down a hill 2014-02-06
flo pose la question :
michelle walks 4 km to the top of a hill at 3 km/h then immediately walks back down at an average speed of 5 km/h what is her average speed for the 8km walk
Penny Nom lui répond.
Related rates 2014-01-30
Veronica pose la question :
A container is the shape of an inverted right circular cone has a radius of 1.00 inches at the top and a height of 5.00 inches. At the instant when the water in the container is 1.00 inches deep, the surface level is falling at the rate of -2.00 inches/second. Find the rate at which the water is being drained.
Penny Nom lui répond.
Two nonlinear equations 2014-01-26
Naryn pose la question :
(1÷x) + (1÷y) = (7÷12)
xy = 12

Penny Nom lui répond.
A rectangular shaped property 2014-01-17
Donna pose la question :
If I I have property that is rectangle shaped. I I know the ends are 100 feet how many feet would the sides be to make 5.4 acres
Penny Nom lui répond.
A rectangle inscribed in a circle 2014-01-10
Marian pose la question :
A 16 cm by 12 cm rectangle is inscribed in a circle. Find the radius of the circle.
Penny Nom lui répond.
Radio direction finders 2014-01-09
Nathan pose la question :
Radio direction finders set up two points A and B, which are 2.5 miles apart on an east-west line. From A, it is found that the bearing of a signal from a radio transmitter is N36.33 degress E, while from B the bearing of the same signal is N53.67 degrees W. Find the distance of the transmitter from B.
Penny Nom lui répond.
Two tuna boats 2014-01-09
amanda pose la question :
Two tuna boats start from the same port at the same time, but they head in opposite directions. The faster boat travels 10 knots per hour faster than the slower boat. At the end of 8 hours, they were 272 nautical miles had each boat traveled by the end of the 8 hour period?
Penny Nom lui répond.
Distance from a point to a line 2013-12-28
Sue pose la question :
I need to find the distances from the west line on 1st Take Point and 2nd Take Point.
Thanks,
Sue

Penny Nom lui répond.
Analytic Geometry 2013-12-18
fRitz pose la question :
if (x,4) is equidistant from (5,-2) and (3,4), find x.
Penny Nom lui répond.
The area of an irregular octagon 2013-11-18
zafar pose la question :
if i have a rectangular octagon then how i can find its area 1. The length of rectangle is 42 and the width is 21 and and the base length is 42-12 =30 i mean the length of base =30
Penny Nom lui répond.
One train overtaking another 2013-11-11
kiran pose la question :
two trains of equal length are running in parallel tracks in the same direction with the speed of 60km/hr and 90km/hr respectively the latter completely crosses the former in 30 seconds the length of each train is in mtr
Penny Nom lui répond.
The average time per mile for a marathoner 2013-11-04
Peter pose la question :
a runner ran a 26.2 mile marathon in 2hours 8minutes and 24secounds. the question is, what was his average time for each mile that he ran?
Penny Nom lui répond.
Substitution type simultaneous equations 2013-11-03
Kayla pose la question :
I am having problems with substitution type simultaneous equations, when the variable you are substituting is a algebraic one:
y=x^2-3x+4 and 3x-2y=1
I have rearranged 3x-2y=1 to get x=(1+2y)/3 but when I substitute this x value into the other equation, I get the wrong answers!
Would appreciate any help! Thank you.

Penny Nom lui répond.
The perimeter of a rectangle 2013-10-24
sana pose la question :
if the length is given 70 m and the breadth is given as 40 m find the perimeter of the rectangle
Penny Nom lui répond.
Four tangent circles 2013-10-09
Nilesh pose la question :
Four circular cardboard pieces, each of radius 7cm are placed in such a way that each piece touches two other pieces. How to find the area of the space enclosed by the four pieces?
Please let me know.

Robert Dawson lui répond.
A pool, a school, a park and home 2013-09-24
Selena pose la question :
The distance from the park to the pool is the same distance as the distance from your house to school. The school is between the pool and your house. Prove that the distance from the park to the school is the same distance from the pool to your house.
Robert Dawson lui répond.
A rectangular hyperbola 2013-09-19
Soumya pose la question :
Is the graph of an inverse variation a RECTANGULAR HYPERBOLA? If it is, then how can be the equation of a rectangular hyperbola be xy=constant , whereas in the books it is written that the graph of a rectangular hyperbola is- x^2-y^2=a^2?
Chris Fisher lui répond.
Similar rectangles 2013-08-17
Mattie pose la question :
The dimensions of a rectangular-shaped picture frame are 14 inches long and four inches wide. Which dimensions below represent another frame that i geometrically similar>

a. l=49 in. and w=14in.
b. l=7in and w=3in
c. l=21in and w=8in
d. l=24in and w=14in

thanks

Penny Nom lui répond.
Equal ordinate and abscissa 2013-08-15
sonit pose la question :
the slope of tangent to the curve y=(4-x^2)^1/2 at the point, where the ordinate and abscissa are equal, is
Penny Nom lui répond.
What is the original speed? 2013-08-10
MJ pose la question :
If a truck increases its average speed by 10 km/h it can cover 60 km at the original speed in the same time that it can cover 80 km at the faster speed. What is the original speed?
Penny Nom lui répond.
Simultaneous equations 2013-07-10
Warren pose la question :
solve this simultaneous equation:
xy=4
2x+3y=14

Penny Nom lui répond.
Distance as a function of acceleration 2013-07-10
Tom pose la question :
If you start at a stoplight and your acceleration is 16t - t^2, how far have you gone after 8 seconds?
Penny Nom lui répond.
Diego and his dog 2013-07-09
William pose la question :
john went hunting and walked at a speed of 4 km/h. one hour later, Diego and his dog went to meet john with a speed of 6 km/h and the dog was running between john and diego until they meet up with a speed of 18 km/h. After Diego meets john, how much distance did the dog run?
Penny Nom lui répond.
Water use in a rectangular flush tank 2013-05-10
milo pose la question :
A rectangular flush tank 22" by 71/4 contains water to depth of 17" how many gallons of water will be saved if a conservation device reduces the capacity to 3/5 of this amount? And reduced to the nearest tenth
Penny Nom lui répond.
A triangle and an incircle 2013-05-09
Max pose la question :
On my Geometry Test about tangent, chord, and secant lengths, my teacher gave an extremely difficult problem.
It was a Circle inscribed in a Triangle with all triangle sides being tangents and lengths were given. My class was told to find the length of each segment of the line. The points on each line were the vertexes of the triangle, and the point where the line hits the circle.
Please explain how someone could do this.

Chris Fisher lui répond.
4 linear equations with 3 unknowns 2013-04-12
Marian pose la question :
how to solve for 3 unknowns in 4 simultaneous equations
Penny Nom lui répond.
The distance between 2 lines in 4D 2013-04-01
samane pose la question :
how can i measure the distance between 2 lines in 4D??
Chris Fisher lui répond.
Simultaneous equations with fractions 2013-03-31
Terence pose la question :
5/x-6/y=1 17/x+30/y=16 I been spending whole day to solve this question. Would be very grateful if you can help I try The denominator value is a equations term which make is simultaneous equations so hard.
Penny Nom lui répond.
A shortest distance problem 2013-03-28
LYNDELL pose la question :
I have a right triangle and know the length of all sides. How do I calculate the shortest distance from the vertex of the 90 degree angle to the hypotenuse?
Penny Nom lui répond.
Tangents to the curve y = x^3 2013-03-24
Ethan pose la question :
How many tangent lines to the curve y = x^33 pass through the point (2, 4)? For each such line, and the exact coordinates of the point of tangency on the curve.
Penny Nom lui répond.
Trigonometry 2013-03-23
Tizoc pose la question :
I am in a trig class and I have a conflict. When solving the length of a side, I know what trig function to use, but I do not know what angle to use in a calculator. To make this a little more understandable, if I have all the angles available in a right triangle and I use the tangent function, how do I know what to use?
Heres what I do not know what to put in my calculator: Tan(?)
Thanks in Advance!

Penny Nom lui répond.
The dimensions of a rectangle 2013-03-19
stephanie pose la question :
the length of a rectangle is 5m more than twice its width, and the area of the rectangle is 88m^2 find the demensions of the rectangle
Penny Nom lui répond.
Fencing a parcel of land 2013-03-11
Koleen pose la question :
How much fencing do I need for an 56,850 parcel of land for a 15 stable horse barn
Penny Nom lui répond.
6 miles in 28 minutes what's my average speed? 2013-03-05
lynda pose la question :
6 miles in 28 minutes what's my average speed?
Penny Nom lui répond.
The tangent to a circle at a point on the circle 2013-02-22
Andrew pose la question :
What is the equation of the line tangent to the circle with equation x^2+y^2=25 at the point (-4,3)
Penny Nom lui répond.
An electron in a TV tube 2013-02-15
anu pose la question :
an electron in a TV tube is beamed horizontally at a speed of (50^6) m/sec. towards the face of a tube 40 cm away about how far will the electron drop before it hits? no information has been provided of initial height from where it is beamed.
Robert Dawson lui répond.
A word problem involving toys 2013-02-14
sandy pose la question :
Each boy gets 5 toys.Each girl gets 3 toys.There are 150 pupils.
The boys had 74 more toys than girls.
How many boys?
How many girls?

Penny Nom lui répond.
Simultaneous equations 2013-02-10
Michael pose la question :
2P + 1/3V =8
3P - 2/V=5

Penny Nom lui répond.
A journey of two parts 2013-02-06
Natalie pose la question :
Mr Lim drove at 70 km per hour for 1 hour and 30 minutes. He then drove another 55 km. if his average speed for the whole journey was 80km per hour, what was his speed for the 55 km journey?
Penny Nom lui répond.
The area of a rectangle 2013-01-29
Bali pose la question :
if the length of the rectangular field is decreased by 5m, its area is decreased by 70 sqm. if the width is increased by 6m, the area is increased by 180 sqm. determine the length and width of the rectangular field?
Penny Nom lui répond.
How fast are we approaching each other? 2013-01-11
Heather pose la question :
If I am skating at 7 mph, and a car drives towards me at 15 mph, how fast are we approaching each other?
Penny Nom lui répond.
How fast is the distance between the aircraft and the car increasing? 2012-10-24
Steven pose la question :
At a certain instant an aircraft flying due east at 240 miles per hour passes directly over a car traveling due southeast at 60 miles per hour on a straight, level road. If the aircraft is flying at an altitude of .5mile, how fast is the distance between the aircraft and the car increasing 36 seconds after the aircraft passes directly over the car?
Penny Nom lui répond.
Two swimmers 2012-10-22
Emily pose la question :
Two swimmers start from opposite sides of the pool. Each swimmer swims the length of the pool and back at a constant rate. They pass each other for the first time 40 feet from one side of the pool and for the second time 45 feet from the other side of the pool. What is the length of the pool?
Penny Nom lui répond.
Two congruent circles in a rectangle 2012-10-20
Alexander pose la question :
Have you ever solved a problem, in which you have a rectangle, from which you need to cut the largest two circles of equivalent diameter? I bisected a rectangle diagonally, but the circles, while tangent to two of the sides, are not tangent to eachother. Can you devise a method for two equivalent circles, that are tangent to two sides, are also to eachother?

Take for example a piece of paper, Each if the two largest circles has a diameter that is greater than the distance to the midpoint of the diagonal bisector of the rectangle.

Chris Fisher lui répond.
A tank with an inner walled compartment 2012-10-12
don pose la question :
I have a tank 20 feet diameter, 19' 8" tall with an inner walled compartment that has a 7' 6" radius arc with in the tank. I need to figure out the volume of the inner area and the volume of the larger area.
Harley Weston lui répond.
A word problem involving a fraction 2012-10-12
Derrick pose la question :
If the numerator and denominator of a fraction are both decreased by 1 the fraction becomes 2/3. If the numerator and denominator are both increased by 1 the fraction will be 3/4. Find the original fraction. How to do?
Penny Nom lui répond.
Four tangent circles 2012-10-04
renu pose la question :
inside of a circle K of radius length measure R,three circular discs A,Band C each of radius r are placed so that each touches the other two and K . express R in terms of r. in the space between K, A and B , another circular disc D is placed which just touches K, A and B. if the radius is s, show that (6+root3)s=(2+root3)r
Penny Nom lui répond.
The perimeter of a rectangle 2012-09-19
aretha pose la question :
calculate the perimeter of a rectangle with the long side 462ft x 9inches and the short side 50% less.
Penny Nom lui répond.
The dimensions of a rectangle 2012-09-12
Becky pose la question :
A rectangle has an area of 48 square inches and perimeter of 32 inches. Find the dimensions of the rectangle.
Penny Nom lui répond.
The volume of fluid in a tank 2012-09-06
Dave pose la question :
I have vertical round flat bottom tanks of various dimensions. It is easy to find total volume but I would like to know how to figure out the coversion factor to go from how many centimeters of liquid is in the tank to the number of total cubic meters of volume. So if my float gauge on the tank says there is 50 cm of fluid in the tank, how many cubic meter of total volume is there?
Harley Weston lui répond.
A tangent to f(x) = 1/x 2012-09-04
Steven pose la question :
Consider the graph of the function f(x) = 1/x in the first quadrant, and a line tangent to f at a point P where x = k. Find the slop of the line tangent to f at x = k in terms of k and write an equation for the tangent line l in terms of k.
Penny Nom lui répond.
The area of a rectangle 2012-08-31
mario pose la question :
The area of a triangle when on side is x and the other is x+6
Harley Weston lui répond.
Problem solving 2012-08-15
Sugavanas pose la question :
If length of a rectangle exceeds its width by 5 m. if the width is increased by 1m and the length is decreased by 2 m, the area of the new rectangle is4 sq m less than the area of the original rectangle. Find the dimensions of the original rectangle.
Penny Nom lui répond.
A plane travelling with the wind and against the wind 2012-08-03
Gwen pose la question :
The time of a plane trip of 450 miles, with the wind is 3/5 the time of the return trip against the wind. If the plane travels 120 mph in still air, what is the wind speed?
Penny Nom lui répond.
The area of a rectangle 2012-07-24
michael pose la question :
the dimension of the rectangle are (x+5) and (x-3) find its area
Penny Nom lui répond.
A cubical tank 2012-07-07
jake pose la question :
a storage tank is in the form of a cube. when it is full of water,the volume of water is 15.625 m cube. if the present depth of water is 1.3m, find the volume of water already used from tank
Penny Nom lui répond.
A cyclist a jogger and a fly 2012-06-04
Emd pose la question :
A cyclist & a jogger are 20 miles apart. Cyclist goes 20 mph & jogger 7mph towards each other. A fly starts on nose of cyclist & flies at 20 mph from cyclist to jogger & back & forth until they meet. How far has the fly travelled?
Penny Nom lui répond.
Romeo and Juliet live 40 miles apart 2012-05-18
Abigaíl pose la question :
Romeo and Juliet live 40 miles apart. Romeo jogs 8mph, while Juliet “fast walks” at 4mph. They leave their houses at the same time and journey toward each other.
a) How many hours after they start will they meet?
b) Approximately how many miles from Romeo’s house is their meeting point?

Penny Nom lui répond.
Math, time and rate 2012-05-18
Abigaíl pose la question :
Romeo and Juliet live 40 miles apart. Romeo jogs 8mph, while Juliet “fast walks” at 4mph. They leave their houses at the same time and journey toward each other.
a) How many hours after they start will they meet?
b) Approximately how many miles from Romeo’s house is their meeting point?

Penny Nom lui répond.
Cycling and running 2012-05-07
liz pose la question :
a biathlete travels 20 miles in 2.25 hours. She cycles part of the way at 12 mph and runs the rest at 5 mph. How far did she run?
Penny Nom lui répond.
The maximum distance from the vertex of a triangle 2012-05-02
David pose la question :
There are three towns A,B,and C, equi-distant apart. A car is 3 miles from town A, and 4 miles from town B. (ie, somehwere outside of the triangle which the three towns form) What is the maximum distance that the car can be from town A?
This was asked as quiz question in my local pub last Sunday.
The answer is 7. How do I prove it?
Best regards. David in Denton.

Robert Dawson and Chris Fisher lui répond.
The dimensions of a rectangle 2012-04-30
Nikki pose la question :
Name the dimensions of a rectangle that has the same area as this triangle? I found the area of the triangle, which is 30. What do I have to do in order to complete this math problem?
Penny Nom lui répond.
A tangent line to a circle 2012-04-14
Novelyn pose la question :
find an equation of the line tangent to a circle with equation x^2+y^2+6x-8y-27=0 at the point P(1,-2)
Penny Nom lui répond.
Two cars approach a right-angled intersection 2012-04-10
Michael pose la question :
Two cars approach a right-angled intersection, one traveling south a 40km/h and the other west at 70km/h. When the faster car is 4km from the intersection and the other case if 3km from the intersection, how fast is the distance between the car cars changing?
Penny Nom lui répond.
A rectangular prism 2012-04-05
Tori pose la question :
How do you find the base height if the base width is 10ft. The height is 7ft. And the volume is105ft.
Penny Nom lui répond.
How long will it take lee to catch up with jodie? 2012-03-21
kirsten pose la question :
for example, if jodie is on the bus travelling at 10 m.p.h and lee is walking at 4 m.p.h how long will it take lee to catch up with jodie?? what is this mathematical name for this
Harley Weston lui répond.
The dimensions of a rectangle 2012-03-13
irvyn pose la question :
if you are only given the area and the perimeter how do you find the dimension?
Penny Nom lui répond.
A water tank is in the shape of a truncated cone 2012-03-08
Victoria pose la question :
Suppose you have a water tank in the shape of a truncated cone. The larger diameter is K, the smaller diameter is K/2, and the height is also K (all measured in meters). The force of gravity on an object of mass, m, is F=9.8m (measured in Newtons). The density of the water is 1000 kilograms per cubic meter. What is the volume of the tank and how much mass will the tank have when it is full?
Penny Nom lui répond.
The area and perimeter of a rectangle 2012-03-01
RAJIB pose la question :
PEREMETER OF A RECTANGLE IS 24. FIND THE AREA ?
Penny Nom lui répond.
Measuring the liquid in a horizontal tank 2012-02-28
Philip pose la question :
I have a steel gas tank that is 3' dia X 5' length. The total volume is 1000 litres. But how much is left when I use a stick and measure 6" from the bottom or 12" or 24" ?? Is there a formula to use for this task?

Thanks.

Harley Weston lui répond.
Margie threw a ball 2012-02-16
mary pose la question :
at 9:45 Margie threw a ball upwards while standing on a platform 35ft above the ground. The height after t seconds follows the equation: h(t)= -0.6t^2 +72t+35
a) what will be the maximum height of the ball?
b)how long will it take the ball reach its maximum height??

Harley Weston lui répond.
Jack and Kate set off in their cars ... 2012-02-13
akiri pose la question :
Jack and Kate set off in their cars from the same point to travel the same journey. Jack has a start of eight minutes before Katie sets off. If Jack travels at 50mph and Katie travels at 75mph, how many miles will be travelled when the two cars are level?
Penny Nom lui répond.
A road around a garden 2012-02-07
Manu pose la question :
Inside a square garden of side 158m, a road 4m wide is built all around. What is the area of the remaining part of the garden?
Penny Nom lui répond.
There is a police officer in pursuit of suspect 2012-02-01
Jay pose la question :
There is a police officer in pursuit of suspect. They suspect is driving on a straight road traveling at 79 mph, the officer is 233 yds away, traveling at 92 mph, the suspects car 5 ft long and the officers car is 5.3 ft long, how long will it take to have the front of the officers car, equal to the front of the suspects car down to the tenth of a second.
Harley Weston lui répond.
The dimensions of a rectangle 2012-01-31
Dazz pose la question :
Hi I was wondering how to find the length of a rectangle if you know the area is 484 square inches And the length is 10 square inches or 22 square inches?
Thanks~Dazz

Penny Nom lui répond.
Two cars in a race 2012-01-30
Christine pose la question :
In a car race, the speed of one car is 120kph and the other car is 105 kph. If the faster car finished the race 20 mins before the slower one, what was the distance of the race? Thanks for the answer and the previous answer to my question.
Penny Nom lui répond.
Tangent of theta 2012-01-17
stahl pose la question :
explain what the 'tangent of theta' means. Draw and label a diagram to help with your explanation.
Harley Weston lui répond.
Brian on his bike 2012-01-16
tiffany pose la question :
Brian rides his bike 0.29 miles per minute. If it takes him 22 minutes to ride his bike to his friend's house, how far away does his friend live?
Penny Nom lui répond.
Running 5 km 2012-01-12
Fayeann pose la question :
What amount of time will it take a person running 7 m/s to travel a distance of 5 km?
Penny Nom lui répond.
An equilateral triangle and some circles 2012-01-10
tushar pose la question :
draw an equilateral triangle with side 6cm.draw 3circles with radii 3cm on each angular point of triangle.draw common tangent on each of two circles
Penny Nom lui répond.
The dimensions of a rectangle 2012-01-06
joseph pose la question :
The perimeter of a rectangle is 72 inches. The length of the rectangle is three more than 2 times the width of the rectangle. What is the length of the rectangle? Write and solve an equation to determine the dimension of the rectangle.
Penny Nom lui répond.
A straight line distance 2012-01-06
Margaret pose la question :
If you traveled 300 miles east and 275 miles north, how many miles would you save by going in a straight line?
Penny Nom lui répond.
Jennifer wants to fence in her backyard 2011-12-09
Val pose la question :
Jennifer wants to fence in her backyard. A yard is rectangular and is 15 feet by 12 feet. One 12-foot side is against the house so it does not need fencing. How many feet of fencing does Jennifer need?
Penny Nom lui répond.
A 3000 gallon tank 2011-12-08
Delores pose la question :
I need to know what size to build a tank to hold 3000 gallons of water one side needs to be 8 ft width X 6 ft height how long does it need to be?
Penny Nom lui répond.
Two trains passing each other 2011-12-07
Tamkeen pose la question :
two trains 245m and 315m long are travelling toward each other at 90km/h and 54km/h respectively on parallel lines . how long do the train take to pass one another train the time they meet each other?
Penny Nom lui répond.
Uniform acceleration 2011-12-06
Android pose la question :
At a certain instant, two cars A and B are 2000 ft apart. At this instant, car A is traveling at 15 miles/hr. and accelerating at 3 ft/s^2 while B is moving towards A at 30 miles/hr. and an acceleration of 2 ft/s^2.

Find the ff:
a.) The possible time of their collusion in minutes.
b.) The distance in ft. each has traveled before collusion.

Penny Nom lui répond.
Two boats 2011-11-30
Shayan pose la question :
A boat is traveling 20 miles per hour when it passes a lighthouse. another boat is traveling at 15 miles per hour when it passes a point. the lighthouse and the point are 175 miles apart. when will the boats pass each other?
Penny Nom lui répond.
Water pouring into a conical tank 2011-11-21
Patience pose la question :
Hi my name is patience and I'm having a problem with this question.
Water pours into a conical tank of semi vertical angle 30 degrees at the rate of 4 cm^3/s, where h is the depth of the water at time t. At what rate is the water rising in the tank when h = 10 cm?
Thank you

Penny Nom lui répond.
Lines tangent to y^2=4x 2011-11-11
Reuchen pose la question :
Find equations of the lines tangent to y^2=4x and containing (-2,1).
Penny Nom lui répond.
The average speed for the whole journey 2011-10-30
Shahzad pose la question :
a train travels 68 Km at an average speed of 51Km/h. It then travels another 20Km at an average speed of 40Km/h before reaching its destination. Calculate the average speed for the whole journey?
Penny Nom lui répond.
One central circle and three tangent circles 2011-10-16
Margaret pose la question :
You have one central circle and three or more circles tangent to the outside of the circle of varying radii. You know the x,y coordinates of the centers of the other circles. If you now remove that central circle (and pretend you never knew where it was), can you calculate its center in x,y coordinates?
Chris Fisher lui répond.
What is the speed of the boat in still water? 2011-10-07
Hannah pose la question :
The speed of a stream is 3 mph. A boat travels 10 miles upstream in the same time it takes to travel 16 miles downstream. What is the speed of the boat in still water
Penny Nom lui répond.
Chuong and Hassan drive to work 2011-10-04
Dilshad pose la question :
Chuong and Hassan both drive 40 km from home to work each day. One day Chuong said to Hasssan, "If you drive home at your usual speed, I will average 40 kmph faster than you and arrive home in 20 minutes less time." Find Hassan's speed.
Penny Nom lui répond.
A rectangle of largest possible area 2011-09-16
mary pose la question :
Steven has 100 feet of fencing and wants to build a fence in a shape of a rectangle to enclose the largest possible area what should be the dimensions of the rectangle
Penny Nom lui répond.
A tangent to the earth 2011-09-03
Vickram pose la question :
I have a math problem regarding tangent and circle. My example is as follows: if a long flat ruler measuring 1500 miles is placed on top of earth which has a radius of 3960 miles what part (length) of the tangential ruler will actually be touching the earth and what two parts will not?
Chris Fisher lui répond.
Driving to meet Mary 2011-08-24
Denise pose la question :
mary leaves St Paul traveling 2000 miles @ 55 MPH; John leaves LA traveling 2000 miles @ 45 MPH how many miles will John had traveled to meet mary?
Penny Nom lui répond.
Three tangent circles 2011-08-21
maribie pose la question :
three discs are tangent externally distances between their centers are 23cm, 15cm, and 20cm. find their radii.t
Penny Nom lui répond.
Three tangent circles 2011-08-19
hanniel pose la question :
two coin are tangent to a third coin internally and are tangent to each other externally. The distance between their centers are 14 mm, 17mm, and 5mm. find their radii
Penny Nom lui répond.
The height of a fluid in a horizontal tank 2011-07-24
jason pose la question :
Same set up as many others, cylindrical tank on its side, but I am interested in defining the change in volume and/or fluid level as a function of time at a constant volumetric outflow. I plan on hooking a pump to the tank so "gpms' will be constant. I have a couple different sized tanks and pumps so I want a general equation. Thanks for your help.
Harley Weston lui répond.
A rectangle is inscribed in a circle 2011-07-17
Alexea pose la question :
A rectangle is inscribed in a circle of diameter 15in. Express the perimeter as a function of the width x.
Penny Nom lui répond.
Achilles and a turtle 2011-07-01
Jean pose la question :
Achilles and a turtle are having a race. The turtle starts 45m ahead of Achilles and Achilles is twice as fast as the turtle. If turtle runs at 1m/s,how far would the turtle have run before he is outrun by Achilles?
Penny Nom lui répond.
Two trains 2011-06-07
Lynn pose la question :
If the 1st train goes 60 mph and the 2nd train leaves 10 minutes later = at a speed of 70 mph, how long does it take to catch up with the 1st = train.
Penny Nom lui répond.
A line tangent to f(x)=1/x 2011-06-05
Michael pose la question :
A line tangent to f(x)=1/x in the first quadrant creates a right triangle with legs the x-axis and the y-axis. Prove that this triangle is always 2 square units regardless of where the point of tangency is.
Penny Nom lui répond.
How many meters long should the race be? 2011-05-26
Lee pose la question :
Nathan can walk at a rate of two meters per second while David can easily go three-and-a-half meters per second. David offers Nathan a 45 meter head start. How many meters long should the race be in order for Nathan to win by a nose
Penny Nom lui répond.
The dimensions of a rectangle 2011-05-08
yolanda pose la question :
If the length of a rectangle is 3ft less than twice its width and the area of the rectangle is 54ft^2,what are the dimensions of the rectangle?
Penny Nom lui répond.
Three tangent circles 2011-05-01
mark pose la question :
Three circles of radii 24 cm, 32 cm, and 42 cm are externally tangent to each other (each is tangent to the other two). Draw a diagram and using the Law of Cosines find the largest angle of the triangle formed by joining their centres.
Penny Nom lui répond.
The area of a rectangle 2011-04-30
Hayley pose la question :
A rectangles width is exactly twice its length. The area of the rectangle is 450 square feet. What are the length and width of the rectangle?
Penny Nom lui répond.
The quadratic with two given roots and a constant term 2011-04-19
Lindah pose la question :
how do I food quadratic with two given roots and a constant term?
Penny Nom lui répond.
A concrete walk around a pool 2011-04-15
Skipper pose la question :
I want to know the answer if you were to want a pool to be 20 ft by 30 ft and wanted a 5 ft border around it what would be the dimension of the whole area plus concrete walk
Penny Nom lui répond.
How far is it from the control tower? 2011-04-11
Varun pose la question :
An aircraft is vertically above a point which is 10 kms west and 5 kms north of a control tower. if the aircraft is 4000 mts above the ground,how far is it from the control tower?
Penny Nom lui répond.
Eliminate y 2011-04-07
Lynn pose la question :
2x + y = 8
y + 3z =5
z + 2w =1
5w + 3x = 9

Form three equations with y eliminated

Penny Nom lui répond.
Two ships 2011-04-05
Gevork pose la question :
Ship A is sailing due south at 16 mph. At the same time, a second ship B, 32 miles south of A, is sailing due east at 12 mph.
(a) at what rate are they approaching or separating at the end of one hour?
(b) At what rate are they approaching or separating at the end of two hours?
(c) When do they cease to approach each other and how far apart are they at that instant.

Penny Nom lui répond.
The perimeter of a rectangle 2011-04-04
aspen pose la question :
the perimeter of a rectangle is twice the sum of its length and its width. the perimeter is 40 meters and its length is 2 meters more then twice its width. what is the length?
Penny Nom lui répond.
The rectangle is reduced to 90% of its original size 2011-03-31
stephon pose la question :
A rectangle has a length of 4cm and a width of 8cm.

If this rectangle is reduced to 90% of its original size what will be the new length

Penny Nom lui répond.
Two boats 2011-03-29
Mamie pose la question :
Two speed boats leave the port of San Francisco traveling in opposite directions at the same time.One boat travels 8 knots per hour faster than the other.After one day's travel they are 1,920 nautical miles apart.What are the speeds of the two boats.
Penny Nom lui répond.
Sample Standard deviation 2011-03-16
Iris pose la question :
Help please: me on this type of math problem I can get through step one after that I get lost. Maybe you can explain it to me in a easier way to get the correct results. I have read the examples, but I am still lost cannot move on until the next practice until I get this one

Sample standard deviation
The following are distances (in miles) traveled to the workplace by employees of a certain computer company.

15,29,32 28 18 28
Find the standard deviation of this sample of distances. Round your answer to at least two decimal places.

Penny Nom lui répond.
A family of circles 2011-03-01
steffi pose la question :
Find the equation of the family of the circle passing through the the point of intersection of x^2+ y^2 -4x-28=0 and x^2 +y^2 -4x-20+52=0; the member tangent to x=7.
Penny Nom lui répond.
Find the dimension of the original rectangle 2011-02-28
sandra pose la question :
the perimeter of a rectangle is 40 cm. if the length were doubled and the width halved, the perimeter would be increased by 16cm. Find the dimension of the original rectangle
Robert Dawson lui répond.
Slicing a rectangular parallelepiped 2011-02-23
tom pose la question :
a) Pass a plane containing a vertex of a rectangular parallelepiped and a diagonal of a face not containing that vertex to cut a pyramid from the parallelepiped. What fraction of the volume of the parallelepiped is the volume of the pyramid thus cut off?

b)Pass a plane through a cube of edge 8 in so that the section formed will be a regular hexagon. Through each side of the hexagon pass two planes, one plane containing one of the two vertices of the cube which are farthest away from the plane of the hexagon, the other plane containing the diagonally opposite vertex of the cube. Find the volume of the solid bounded by these planes.

c)three of the edges of a rectangular parallelepiped that meet in a point are also the lateral edges of a pyramid. What fraction of the parallelepiped is this pyramid...?

you know the my only problem is how to illustrate this one...if only i could ...can you help me....all I need is the drawing and I can do the rest ..it's fine if you'll only answer any of these but I'll be thankful if you will do the three :)....

Penny Nom lui répond.
Two conical tanks 2011-02-17
rustom pose la question :
Two vertical conical tanks (both inverted) have their vertices connected by a short horizontal pipe. One tank, initially full of water, has an altitude of 6 ft. and a diameter of base 7 ft. The other tank, initially empty, has an altitude of 9 ft., and a diameter of base 8 ft. If the water is allowed to flow through the connecting pipe, find the level to which the water will ultimately rise in the empty tank (Neglect the water in the pipe.)
Penny Nom lui répond.
The equation of a circle 2011-02-14
Cristela pose la question :
find the equation and all the information in General Form and Standard Form of the Circle that will passed trough the point (2,3) (6,1) (4,-3)
Stephen La Rocque lui répond.
Two tangent circles 2011-02-09
xhesika(jessica) pose la question :
Two circles of radius 10 are tangent to each other.A tangent is drawn from the centre of one of the circles to the second circle.To the nearest integer find the area of the shaded region.
Penny Nom lui répond.
A tangent to a circle 2011-02-06
debz pose la question :
what is the formulae of the tangent to a circle.... our teacher gave us a lot of homework.. and she ask us to find the formulae by ourselves..
Penny Nom lui répond.
Calibrating a conical tank 2011-02-05
Bill pose la question :
Hi, I have a round tank with tapered sides where I know the diameter at the top and bottom. Is there a formula I can use to calculate the volume by measuring from the bottom up the side (at the angle of the side) to any given point? Thanks, Bill
Stephen La Rocque and Penny Nom lui répond.
A fence around a water tank 2011-02-01
Heath pose la question :
I am building a fence around a water tank. the fence is to be in the shape of a normal octagon. The tank has a circumference of 57 ' 6''. I would like the fence to be 3 ft from the tank at the skinny point . How would I calculate(for the simple guy) where to set each of my 4x4 posts at the 8 corners. Any help would be greatly appreciated.
Harley Weston lui répond.
The area of a rectangle 2011-01-31
T.S. pose la question :
for which value of w does the rectangle below have an area of 864 square units if sides are width=w+15 and length=w-15
Penny Nom lui répond.
Points with distance 5 from the point (-2, -1) 2011-01-19
Alexa pose la question :
Find all points having a x-coordinate of 2 whose distance from the point (-2, -1) is 5.
Penny Nom lui répond.
A rectangle 2011-01-16
meg pose la question :
if a rectangle has a length that is 3cm less than 4 times its width and its perimeter is 19cm, what are the dimension?
Penny Nom lui répond.
A cylindrical tank 2011-01-16
tom pose la question :
A cylindrical tank, 1 ft in diameter, length 6 ft , is placed so that its axis is horizontal. How many pounds of water will be used in filling it to a depth of 9in. , if water weighs 62.4 lbs. per cu. ft.?
Penny Nom lui répond.
Tan(x+pi)-tan(pi-x)=2tan(x). 2011-01-09
Steven pose la question :
Verify the identity:
Tan(x+pi)-tan(pi-x)=2tan(x)

Penny Nom lui répond.
A 400 gallon oil tank 2011-01-08
theresa pose la question :
we have a oil tank that holds 400 gallons of oil currently there is 11/16 volume in the tank how many gallons are there?
Harley Weston lui répond.
What is its speed in miles per hour? 2011-01-06
Miriam pose la question :
An airliner travels 125miles in 15minutes. What is its speed in miles per hour?
Penny Nom lui répond.
A tangent line 2011-01-03
Amanda pose la question :

Question from Amanda, a student:

an equation of the line tangent to y=x^3+3x^2+2 at its point of inflection is
(A) y=-6x-6
(B) y= -3x+1
(C) y= 2x+10
(D) y=3x-1
(E) y=4x+1


Penny Nom lui répond.
The length is twice its breadth 2010-12-09
jenu pose la question :
The length of the rectangular field is twice its breadth. A man jogged around it 5 times and covered a distance of 3 km. what is the length of the field?
Penny Nom lui répond.
80 miles in 40 minutes 2010-12-08
james pose la question :
i travel 8o miles in 40 minutes. how fast am i going in mph
Penny Nom lui répond.
A rectangular solid 2010-12-08
ryan pose la question :
Good day! Have a question on rectangular solids. We were asked to find the dimensions of a rectangular solid, we were only given the volume of the rectangular solid, the total area, and the altitude. I tried using the volume of the rectangular solid and was able to get the area of the base, but I don't know how to get its length and its width. Hope you could help me again. Thanks!
Penny Nom lui répond.
Simultaneous equations 2010-12-05
ryan pose la question :

Question from ryan, a student:

3         4
--   -    --      =     1      (1)
x         y

7       2             11
--   -  --        =   --       (2)
x       y              12


Chris Fisher and Stephen La Rocque lui répond.
Can determine if it is scalene, isosceles, or equilateral 2010-12-01
Jessie pose la question :
find the measures of the sides of triangle KPL and classify each triangle by its sides. my first problem would be K(-3,2) P(2,1) L(-2,-3) ...The three points they give you are the vertices of the triangle and you need to match them up. Draw the triangle and write in the vertices and the related point with the vertex. You will then do the distance formula three times to find the distance of all three sides. Once you have the three sides you can determine if it is scalene, isosceles, or equilateral...using the distance formula how do i solve this?
Penny Nom lui répond.
A rectangular piece of plywood 2010-11-30
Austin pose la question :
A rectangular piece of plywood is trimmed to make it square by cutting a 4cm strip off the top and a 2cm strip off one side. If the area of the original piece is 74cm2 greater than the area of the square, find the dimensions of the rectangle.
Penny Nom lui répond.
What is its speed in still air? 2010-11-28
Shelby pose la question :
An Airplane flies a certain distance in 3 hours going WITH a 40km/hr wind. It travels the same distance in 5 hours when going against the wind. What is it's speed and how long would it take to travel the same distance in still air? Distance = speed x time
Penny Nom lui répond.
The perimeter of a rectangle 2010-11-24
shericka pose la question :
a rectangle has a perimeter of 60cm. its length is 5 times greater than its width. what is its length?
Penny Nom lui répond.
How long will you and your friend be able to talk? 2010-11-23
beket pose la question :
you and your friend leave your home town at the same time your friend travels by train 45 mph directly east while you travel by train 50 mph going directly south you are talking on cell phone but you plan charges extra if the phones are 100 miles apart. How long will you and your friend be able to talk before the charges increase?
Penny Nom lui répond.
A 400 gallon drum 2010-11-04
Jerry pose la question :
Question from Jerry:

I want to build A tank. able to hold 400 gallons of asphalt sealer it will be round . basically like A old fuel oil drum but made with heavy material . math ? was I want tank to hold 400 gallons I think the length of 60" would be perfect. I don't know what diameter or radius of tank needs to be . to make it A 400 Gallon tank

Harley Weston lui répond.
A train passes a car 2010-10-24
Mary pose la question :
A train, whose speed is 75 mph, takes 3 minutes to pass a car that is going 60 mph in the same direction. How long is the train?
Stephen La Rocque lui répond.
A rectangle with rounded corners 2010-10-21
Connie pose la question :
How do you find surface area if the rectangle is 100ft. by 200ft. with quarter circles in the corners with a radius of 20ft. ?
Penny Nom lui répond.
What are the speeds of the boats? 2010-10-21
Adori pose la question :
Two boats leave the port of San Francisco traveling in opposite directions at the same time. One boat travels 8 knots per hour faster than the other. After one day's travel they are 1920 nautical miles apart. What are the speeds of the boats?
Penny Nom lui répond.
John and Mary are 200 miles apart 2010-10-20
Sarah pose la question :
two people, john and mary, are 200 miles apart and leave at the same time to meet. They are driving toward each other at constant rate on the same straight road. John is traveling at 45 mph and Mary is traveling at 35 mph. When they meet, how many miles will they be from john's house?
Penny Nom lui répond.
A commuter airline between two cities 2010-10-19
Adori pose la question :
An airline runs a commuter between two cities that are 720 miles apart. If the average speed of the planes is increased by 40 miles per hour, the travel time is decreased An airline runs a commuter between two cities that are 720 miles apart. If the average speed of the planes is increased by 40 miles per hour, the travel time is decreased by 12 minutes. What airspeed is required to obtain this decrease in travel time?
Penny Nom lui répond.
Two jets leave denver at 9 am. 2010-10-15
Carl pose la question :
two jets leave denver at 9 am. One flying east at a speed of 50 km per hour greater than the other which is traveling west. At 11 am the planes are 2500 km apart. Find their speeds.
Stephen La Rocque lui répond.
Electronic cars around a circular track 2010-10-11
Taylor pose la question :
Cory and Melissa are racing electronic cars around a circular track. They begin at the same time going in the same direction. Cory's car completes a revolution in 35 secs, while Melissa's car completes a revolution in 30 secs. How long will it take them before both cars reach the starting point again simultaneously?
Stephen La Rocque and Penny Nom lui répond.
Two cars 2010-09-30
Amanda pose la question :
Two cars, 142 miles apart, start moving towards each other at the same time. One is moving 3 times as fast as the other. If they meet 1.7 hrs later, find the average speed of the slower car in miles per hour?
Penny Nom lui répond.
Rectangular arrays 2010-09-29
Kim pose la question :
My 4th grader has started working on rectangular array that shows 2 factors of a number.

The problem reads on centimeter grid paper draw as many arrays as you can for each of the #'s 2,3,4, 5,6,7,,11,12,15 and 16. That would be great except I have no idea what they are talking about and I cannot offer any help to my daughter.

Penny Nom lui répond.
The distance between the origin and a moving point 2010-09-24
Norma pose la question :
I am having problems with this question find the rate of change of the distance between the origin and a moving point on the graph of the function below if dx/dt=5 cm/sec y=x^2+2
Penny Nom lui répond.
Limiting Cases in Geometry 2010-09-22
Niki pose la question :
Consider a rectangle inscribed in a circle with a radius or R. What are the possible perimeters for the rectangle?
Stephen La Rocque lui répond.
What is the average speed? 2010-09-21
Cindy pose la question :
A boat travels downstream m nautical miles at d knots. It travels upstream m nautical miles at u knots. What is the average speed for the entire trip?
Penny Nom lui répond.
40 mph for 6 minutes 2010-09-20
Andy pose la question :
If i was traveling at 40 mph for 6 minutes, what is my distance in miles?
Penny Nom lui répond.
How many cubic metres of water can safely be stored in the tank? 2010-09-10
susanna pose la question :
This water tank is a perfect sphere with an inner radius of 12 metres. However, they used inferior materials to build the water tank, and the tank can only withstand a water pressure of 185 kiloPascals. Assume the density of water is exactly 1000 kg/m3, gravity is 9.8 metres/s2, and disregard atmospheric pressure. How many cubic metres of water can safely be stored in the tank? Round DOWN to the nearest whole number (since rounding up could be catastrophic in this instance!), and please submit only a number with no other information.
Robert Dawson lui répond.
Driving north, east and west 2010-09-02
dane pose la question :
suppose that you drive 27 miles north, 31 miles east, 45 miles west, and 14 miles east. how far are you from your starting point?
Penny Nom lui répond.
Three cars 2010-08-30
Anil pose la question :
3 cars are moving at speed of 4 kmph,5.5 kmph and 8 kmph in a circular track.The circular track has a distance of 11 km. What is the time taken for all the 3 cars to meet at the starting point ?
Stephen La Rocque lui répond.
Running 100 km 2010-08-12
thomas pose la question :
Another athlete runs 8 laps every day on the same 400m running track. How many days will it take him to run a total of 100 km?
Robert Dawson lui répond.
Two cars on a circular track 2010-08-12
david pose la question :
If two cars starts to drive at point 1 and go in a circle when will they meet? (one cars speed is faster the other ) all I need is a formula
Tyler Wood lui répond.
How fast is the second car taveling? 2010-07-26
Jeff pose la question :
A car is traveling 75 mph. It takes 12 miles to overtake a second car that was .5 mile ahead. How fast is the second car taveling?
Stephen La Rocque lui répond.
How much longer will it take to reach Toronto 2010-07-22
Rachelle pose la question :
We are taking a trip from Ottawa, ON to Toronto, ON. The total trip is 150 kms and will take us 4.5 hours. We have already driven 108 kms and there is still 42 kms left to go. If we are travelling 110 kms/hr, how much longer will it take to reach Toronto?
Penny Nom lui répond.
An 18ft round pool 2010-07-19
christine pose la question :
will an 18ft round pool fit on a 12x16 ft rectangular cement slab?
Tyler Wood lui répond.
Pursuing Car 1 2010-07-13
Mark pose la question :
Car 1 is traveling down the road at 50mph and passes Car 2 is sitting on the side of the road. Car 2 needs to catch Car 1 one half mile down the road. How fast must Car 2 drive to catch Car 1 if Car 2 waits 10 seconds before pursuing Car 1?
Robert Dawson lui répond.
Half a mile at 50 mph 2010-07-13
Mark pose la question :
How long will it take a car to travel 1/2 mile at 50 mph?
Robert Dawson lui répond.
3 equidistant points on a circle 2010-06-21
Brian pose la question :
We have to line up 3 pins on a lifting bridle to be 120 degrees apart from each other to connect into a lifting assembly.
I know pi*d. I know straight lines connecting these points to each other will result in an equilateral triangle. How does one find these points without using a protractor? There must be a formula (formulae) to work this out mathematically.
r = 10.5 inches
pi*d = 65.9736
3 segments( arcs) = 21.9912 which is the distance along the circumference that the points are from each other.

Penny Nom lui répond.
How many gallons do I need to finish filling the tank? 2010-06-14
Bruce pose la question :
I have a tank on it's side. 44" dia. by 72" long, I'm 6" from having tank full. How many gallons do I need to finish filling tank?
Harley Weston lui répond.
Standard Deviation from a Proportion 2010-06-08
silvestre pose la question :
A large company finds that approximately 17% of all purchases are returned for credit. If the company sells 100,000 different items this year, about how many items will be returned. Find the Standard Deviation.
Janice Cotcher lui répond.
Going to the bike shop 2010-06-07
Omi pose la question :
Marie rode her bicycle from her home to the bicycle shop in town and then walked back home. If she averaged 6 miles per hour riding and 3 miles per hour walking, how far is it from her home to the bicycle shop if her total travel time was 1 hour?
Penny Nom lui répond.
A fuel tank with a broken gage 2010-05-28
Kinsley pose la question :
Hello, I have a fuel tank with a broken gage. It is a 2000 gallon tank. The dimensions are 64" dia. x 146" long. The fuel gage doesn't work, so the only measurement I can do is put a stick in it to see what is left. Currently it is at 19". PLEASE NOTE: the tank is laying on its side, meaning the long side is on the ground. So, how do I determine how much fuel is in the tank by the inches remaining? Thank you very much.
Tyler Wood lui répond.
Liquid in a horizontal tank 2010-05-26
Brian pose la question :
I have a 50' long tank by 12' diameter it is lying down on it side with 12" of Liquid in the bottom i need to know how many gallons of fluid this is? Please Help, I was able to calculate out the Triangle but not the Sector!
Harley Weston lui répond.
How wide a strip has he cut when the lawn is half mowed? 2010-05-24
Arib pose la question :
rectangular lawn has length 40 m and width 30 m. David starts cutting from the outside in. How wide a strip has he cut when the lawn is half mowed?
Penny Nom lui répond.
What is the distance from A to C via B? 2010-05-24
vivianne pose la question :
The distance from A to B is d km and that from B to C is x km. if a bus maintains an average speed of 50km/hr between A and B and 60km/hr between B and C, it takes 3 hours to travel from A to C. If it maintains 60km/hr between A and B and 50km/hr between B and C, the journey takes 8 minutes less. What is the distance from A to C via B?
Penny Nom lui répond.
When will the second truck catch up to the first? 2010-05-22
Josie pose la question :
At 9:00 a.m. a truck leaves the truck yard and travels west at a rate of 45 mi/hr. At 11:00 a.m., a second truck leaves along the same route, travelling at 60 mi/hr. When will the second truck catch up to the first?
Tyler Wood lui répond.
How far am I from the starting point? 2010-05-18
jilayna pose la question :
if i walk 5 miles north, 7 miles east, and 3 miles north again.to the nearest tenth of a mile ,how far,in a straight line, am i from my starting point
Penny Nom lui répond.
Sammy and his motorboat 2010-05-11
Jordan pose la question :
Sammy owns a motorboat that travels 4 miles/hour in still water. It goes 12 miles upstream and 12 miles back again (downstream) in a total of 8 hours. Find the speed of the current of the river.
Penny Nom lui répond.
Line of sight 2010-05-06
David pose la question :
I live in St. Joseph, Michigan and there is an ongoing argument regarding line-of-sight over the horizon.

Standing on a 200 foot high bluff here, people swear they can see the top of the Willis (nee Sears) Tower in Chicago, which is about 1653 feet high.

It is my contention that this is actually a "refracted reflection" and not direct-line-of-sight.

So, to settle the argument, I'd sure like some simple explanation for this, even if-and I hope not-I am incorrect.

David

Harley Weston lui répond.
The equation of a circle 2010-05-04
crystal pose la question :
find the standard form of the circle with center (-2,3) and tangent to the line y=1
Penny Nom lui répond.
40 miles at 50mph 2010-05-02
gill pose la question :
if a car travelled 40miles at 50mph, how long would it take?
Penny Nom lui répond.
When are the cars exactly 40 miles apart? 2010-05-01
Maryanne pose la question :
A car traveling east at 45 mph passes a certain intersection at 3pm. Another car traveling north at 60mph passes the same intersection 25 minutes later. To the nearest minute, figure out when the cars are exactly 40 miles apart.
Penny Nom lui répond.
A rectangular prism 2010-04-27
Savannah pose la question :
A rectangular prism is made of exactly 8 cubes. Find the length, width, and height.
Penny Nom lui répond.
If (x, 4) is equidistant from (5, -2) and (3, 4), find x. 2010-04-21
abeth pose la question :
If (x, 4) is equidistant from (5, -2) and (3, 4), find x.
Find the point on the y - axis that is equidistant from (-4, -2) and (3, 1).

Penny Nom lui répond.
A tangent line to a circle 2010-04-15
Rhonda pose la question :
The Greek method for finding the equation of the tangent line to a circle used the fact that at any point on a circle the line containing the reauis and the tangent line are perpendicular. Use this method to find an equation of the tangent line to the circle x^2+y^2=9 at the point (1,2 square root of 2).
Penny Nom lui répond.
What are the dimensions of the box? 2010-04-13
Steven pose la question :
The longest rod that will just fit inside a rectangular box, if placed diagonally top to bottom, is 17 inches. The box is 1 inch shorter and 3 inches longer than it is wide. How much must you cut off the rod so that it will lie flat in the bottom of the container? What are the dimensions of the box?
Robert Dawson lui répond.
A rectangle problem 2010-04-12
Charlene pose la question :
The ratio of the width to the length of a certain rectangle is equal to the ratio of its length to the difference between its length and twice its width. If the area of the rectangle is 25cm^2, then what are its dimensions? Present a non- algebraic solution?
Tyler Wood lui répond.
The perimeter of a rectangle 2010-04-12
Charlene pose la question :
The area of a rectangle is 390m^2. If its length is increased by 10m and its width is decreased by 6m, then its area does not change. Find the perimeter of the original rectangle.
Tyler Wood lui répond.
The diagonals of a rectangle 2010-03-30
Tabatha pose la question :
The diagonals of a rectangle are 8 units long and intersect at a 60 degree angle. Find the dimensions of the rectangle.
Penny Nom lui répond.
A rectangle inscribed in a circle 2010-03-24
sadiq pose la question :
here is the question, in my mathematics book there is equation of the area of the rectangle inscribed in a circle having equation x^2+y^2=a^2 and the area of rectangle is 4xy=4x(a^2-b^2)^1/2 i don't know what is b but a is surely the radius (i want the derivation for the area of rectangle).
Harley Weston lui répond.
What is the speed of the current? 2010-03-17
Carl pose la question :
If you can row 3 mph in still water and paddle 3 miles upstream and return in 3.6 hours then what is the speed of the current?
Penny Nom lui répond.
Constants and coefficients 2010-03-12
lourdes pose la question :
identify the coefficients, constant term(s), and like terms of the expression.
8x + 9 - 3x
17 - 2a + 5a - 1
7m - 7 + 6m - 6
-10 -15r -22r + 8

Penny Nom lui répond.
The perimeter of a rectangle 2010-03-12
makiah pose la question :
A rectangle has a perimeter of 12 meters.If each side is a whole number of meters, what are the possible dimensions for the length and width?
Penny Nom lui répond.
The distance travelled by a minute hand 2010-03-06
Patric pose la question :
How much distance will the minutes hand of length 14mm of a clock cover in moving from 5 to 10?
Penny Nom lui répond.
Standard form 2010-03-05
Laura pose la question :
How do I change 3y=4x+1 into standard Ax+By=C standard form. This is my son's schoolwork. I homeschool him. I got the answer to the problem as 3y=4x+1, but it needs to be written in standard form and I know it needs to read 4x-3y=-1, but how do I get that answer into standard form. I need to know how to explain it to him. Can you show me? Thank you so much.
Penny Nom lui répond.
The base area of rectangular prism 2010-03-05
Desiree pose la question :
How do you find the base area of rectangular prism that has 4 cm by 4cm by 6cm ?
Penny Nom lui répond.
At what time would Joan catch Jo? 2010-03-04
Rusty pose la question :
If Jo left his house at 6:30am traveling at 5mph and Joan left the same house 7:00am traveling at 8mph, at what time would Joan catch Jo?
Penny Nom lui répond.
The dimensions of a rectangle 2010-03-03
Kirsten pose la question :
A rectangle is twice as long as it is wide. Its area is 128 square meters. What are the dimensions of the rectangle?
Tyler Wood lui répond.
The vertices of an equilateral triangle 2010-02-19
Emma pose la question :
If two of the vertices of an equilateral triangle are (2,1) and (6,5), what are the two possible coordinates of the third side of the triangle? Answer in radical form.
Tyler Wood lui répond.
The equation of a circle 2010-02-18
AHMED pose la question :
find the equation to the circle with centre at the point (1,-1) and touching the straight line 5x+12y=7.
Penny Nom lui répond.
The center of a rectangular room 2010-02-16
Diana pose la question :
Consider a rectangular room, 15 feet wide, 30 feet long and 12 feet high. What is the exact distance from any of the 8 corners of the room and its geometric center? Can you write a generic formula for such a distance? And if we keep the same proportions on all dimensions, can you write an expression for the same distance as a function of the floor perimeter?
Penny Nom lui répond.
The distance from a chord to an arc 2010-02-11
matt pose la question :
hello, I have to layout a radius without being able to pull from the center my radius is 3819.53 feet and i have a chord length of 275.59 feet if i broke that up into 25.05 feet sections how would i calculate the lengths from my chord to that radius?
Robert Dawson lui répond.
Fencing a garden 2010-02-04
kris pose la question :
How many meters of fencing do i need to enclose a garden if the yard is 26 meters long and half as wide?
Penny Nom lui répond.
A decrease in travel time 2010-01-30
Mike pose la question :
if a 100 mile trip averages 50 miles per hour, how much distance does one need to travel at 90 miles per hour to decrease travel time by 10%
Stephen La Rocque lui répond.
The perimeter of a rectangle 2010-01-27
debbie pose la question :
how many dimensions are there to get a perimeter of 400 feet for a rectangle?
Penny Nom lui répond.
A tunnel from Toronto to Montreal 2010-01-25
Dave pose la question :
I want to make a tunnel from Toronto to Montreal (for example)

Something like this http://mathcentral.uregina.ca/QQ/database/QQ.09.09/h/grant1.html
-------------
My coordinates are 45.442455,-73.861340 (Montreal) and 43.442455, -79.861340 (Toronto)

I need to know how to find arc distance, chord distance and radius What websites can i find for this subject Google has many but they are useless (blah blah) websites
LOL
Thanks

Chris Fisher and Robert Dawson lui répond.
A triangle in a rectangle 2010-01-25
Sangya pose la question :
The perimeter of the rectangle is 21 inches. The perimeter of the inscribed triangle is 21 inches. Find the dimensions of the rectangle
Robert Dawson lui répond.
Angle of incline 2010-01-20
Alan pose la question :
how do I fnd the angle of an incline with a measurement of 0.042 with an adjacent of 1.2mtrs?. Thank You
Penny Nom lui répond.
How long will it take to go 1 mile at 80 mph? 2010-01-19
Susann pose la question :
How long will it take to go 1 mile at 80 mph?
Penny Nom lui répond.
How fast am I walking? 2010-01-10
KEVIN pose la question :
IF I WALK 3 MILES IN 28 MINUTES, HOW FAST AM I WALKING?
Penny Nom lui répond.
Gail and Bill drove to the beach 2010-01-10
Nicole pose la question :
Gail and Bill drove to the beach at an average speed of 50mph. They return home over the same road at an average speed of 55mph. The tip took 30 min less time. How far is the beach from their house?
Stephen La Rocque lui répond.
A pair of simultaneous equations 2010-01-09
Yumiko pose la question :
Solve the following pair of simultaneous equations.

x^2 -4x = y^2-4
3y=2x - 3

Penny Nom lui répond.
The maximum area of a rectangle 2010-01-03
Mohammad pose la question :
determine the maximum area of a rectangle with each perimeter to one decimal place?
a)100 cm b)72 m c)169 km d)143 mm

Penny Nom lui répond.
Write a function for the area in terms of x 2010-01-01
Almarie pose la question :
Lauren has 40 feet of metal fencing material to fence three sides of a rectangular garden. A tall wooden fence serves as her fourth side. Write a function for the area of the garden A in terms of x, the width in feet.
Penny Nom lui répond.
A circle problem 2009-12-14
Fawad pose la question :
AP is a tangent at P to a circle centre O, where AP=6cm. The straight line AQC is such that QC= 9cm. Find the length, in cm of AQ.
Chris Fisher lui répond.
f(x)=x+2sinx 2009-12-12
amroziz pose la question :
for which values of x does the graph of f(x)=x+2sinx have horizontal tangent
Harley Weston lui répond.
... the original speed of the car was? 2009-12-08
venkatesh pose la question :
A car travels a distance of 840 miles at a uniform speed if the speed of the car is increased 10 m/h more ,it takes two hours less to cover the same distance ,the original speed of the car was?
options:75 mh,65 m/h,60 m/h,55 m/h,45 m/h .

Claude Tardif lui répond.
Walking at 4/5 of his usual speed 2009-12-05
venkatesh pose la question :
walking at 4/5 of his usual speed a man is 10 minutes too late .find his usual time.
Penny Nom lui répond.
The dimensions of a rectangular room 2009-11-26
crystal pose la question :
. The length of a rectangular room is 7 feet longer than its width. The area of the room is 60 feet. What are the dimensions of the room?
Penny Nom lui répond.
Solving two equations, one with a square root 2009-11-23
kacie pose la question :
y = square root of x+3
x-4y = -7

im having trouble with this problem...i have to find where they intersect.

Harley Weston lui répond.
The triangle formed by the tangent and the coordinates axes 2009-11-23
Nirmala pose la question :
Given that y=1/x, x is not equal to zero. Prove that the area of the triangle formed by the tangent and the coordinates axes is 2.
Harley Weston lui répond.
The fourth vertex of a rectangle 2009-11-11
Ellena pose la question :
The points A(2,-1), B(5,-3), and C(7,0) are the three vertices of a rectangle. Determine he coordinates of the fourth vertex.
Penny Nom lui répond.
At what rate are the people moving apart? 2009-11-01
saira pose la question :
A man starts walking north at 4 ft/s from a point P. 5 minutes later a woman starts walking south at 5 ft/s from a point 500 ft due east of P. At what rate are the people moving apart 15 minute after the woman starts walking ?
Harley Weston lui répond.
Is it a rectangle? 2009-10-29
sefora pose la question :
The coordinates of the vertices of quadrilaterals are given. Draw each quadrilateral on a grid. Determine whether it is a rectangle (show your work)

P(5,1), Q(-4,4), R(-6,-2), S(3,-5)

Penny Nom lui répond.
Standard deviation 2009-10-27
Reggie pose la question :
After you have computed the standard deviation of a set of 40 scores, you discover that the lowest score is in error and should be even lower. Will correcting this error affect the standard deviation?
Penny Nom lui répond.
How far will it travel in 45 mins? 2009-10-27
maison pose la question :
I'm stuck on the formula i dont remeber what it is can you help me out a car is traveling 80km/h how far will it travel in 45 mins
Robert Dawson lui répond.
The area of a rectangle 2009-10-10
Ann pose la question :
given a rectangle with sides a and 2a and diagonal d, find the area of the rectangle as a function of the diagonal,d
Penny Nom lui répond.
Two rectangles 2009-10-08
Lillian pose la question :
A rectangle is 5cm longer than twice its width. The width of another rectangle is 3cm less than the width of the first rectangle and its length is 6cm more than 3 times its width. If the perimeters are equal, find the dimensions of both rectangles
Penny Nom lui répond.
Two jets are traveling towards each other 2009-10-05
jake pose la question :
two jets are traveling towards each other and are 4000 km apart. the rate of one jet is 100 km/h faster than the rate of the other. if the jets pass each other after 2.5 hrs what is the rate of speed of the faster jet?
Penny Nom lui répond.
Three circles 2009-10-02
Brandon pose la question :
There is a quarter circle with a radius of 1. along one eged of it, there is a semi-circl with a diameter of 1, and its center is on the drawn line. there is another semi-circle again with the center on the other drawn line, and this one has an unknown diameter of X. both circles are internally tangent, and are tangent to each other. Find X.
Robert Dawson and Chris Fisher lui répond.
A line tangent to a parabola 2009-10-01
kanchan pose la question :
for what value of c a line y=mx+c touches a parabola y^2=4a(x-a)
Penny Nom lui répond.
How long (distance)did it take to stop? 2009-09-30
mary pose la question :
a car travelling at 50km/h stops in 4 seconds.how long (distance)did it take to stop?
Harley Weston lui répond.
How fast am i going? 2009-09-28
ron pose la question :
how fast am i going if i drive 40 miles in 20 minutes...what is the formula for figuring this out.
Leeanne Boehm lui répond.
How long would it take the students to arrive at their campsite 2009-09-18
amanda pose la question :
..."A group of 5th grade student in New Zealand are going camping. They will hike from Wellingto to Ruapehu. Then they will follow a trail for another 1/2 mile to their campsite." Ok, 1 mile equals 5,280 feet. The class decided one step length is equal to 15 inches and there are 85 steps in 1 minute. Now for the question: About how long would it take the students to arrive at their campsite, if they don't make any stops???
Robert Dawson lui répond.
Average speed 2009-09-11
john pose la question :
Sally travels by car from one city to another. She drives for 20.0 min at 68.0 km/h, 40.0 min at 37.0 km/h, and 51.0 min at 77.0 km/h, and she spends 12.0 min eating lunch and buying gas.

What is the average speed for the trip?

Penny Nom lui répond.
Paddling downstream 2009-09-04
Nicole pose la question :
You head downstream on a river in a canoe. You can paddle at 6 km/h and the river is flowing at 2.4 km/h. How far downstream will you be in 55 minutes?
Penny Nom lui répond.
Simultaneous equations 2009-08-28
onias pose la question :
solve 3/a - 2/b = 1/2 , 5/a + 3/b = 29/12
Robert Dawson lui répond.
The distance traveled on a bike 2009-08-28
Dennis pose la question :
I would like to calculate the distance traveled on a bike based on the size of the tire and on the number of revolutions per minute. This is based on the rider traveling at a constant speed.
Stephen La Rocque lui répond.
The area of a rectangle 2009-08-21
roxanne pose la question :
the dimensions of the rectangle: 3x length and 4x width. What is the area of the rectangle in square units?
Penny Nom lui répond.
Two cars 2009-08-09
Jayna pose la question :
If a car was traveling 20mph east and another car was traveling 30mph west, assuming they were 300 miles apart, at what point would they collide at the center?
Penny Nom lui répond.
A degreaser for a fish tank 2009-07-23
charlie pose la question :
I have a tank that is 10 feet in diameter that I want to put floating degreaser in.The rate for the degreaser is 1/2 gallon per square foot of surface water.How do I figure out how many gallons I need?
Penny Nom lui répond.
A tangent to a circle 2009-07-14
Eric pose la question :
Hi I am trying to complete a packet that has a list of questions to brush up on pre-calculus skills. The question asks "For the circle x^2 +y^2 + 6x - 4y + 3 = 0 find : the equation of the tangent at (-2,5). I have already found the equation for the circle and standard form and the center and radius. However, i do not know how to find the slope or y-intercept of the tangent line. Please help. Thanks.
Stephen La Rocque lui répond.
The surface area of a rectangular pyramid 2009-07-13
Shivani pose la question :
What is the surface area of a rectangular pyramid with a length of 6 inches, a width of 7 inches and a SLANT height of 4 inches.
Penny Nom lui répond.
Simultaneous Equations 2009-07-06
Mukulu pose la question :
Solve the equation simultaneously X/5=(Y+2)/2= (Z-1)/4 ……………….eqt 1 3X+4Y+2Z-25=0 ………………eqt 2
Janice Cotcher lui répond.
A diagonal of a rectangle 2009-07-01
Ruben pose la question :
Please assist me with the following problem: A rectangle has a diagonal that is 3.6 feet longer than the length and 7.1 feet longer than the width. What are the dimensions of the rectangle? Thanks
Harley Weston lui répond.
A boat goes up stream 30 miles and ... 2009-06-29
Mohsin pose la question :
A boat goes up stream 30 miles and down stream 44 miles in 10 hours. Again it goes up stream 40 miles and down stream 55 miles in 13 hours. Find the rates of the stream and of the boat.

I am confused and unable to get an answer. Please help.
Thanks

Robert Dawson lui répond.
The surface area of a tank 2009-06-25
Charles pose la question :
I need to calculate the external wall and top sqft surface area of a tank 54ft od x 15ft high with a dome top 54ft od x 8ft high.
Penny Nom lui répond.
A train crosses a tunnel 2009-06-25
Sabrina pose la question :
A goods train of length one and half kilometres, is moving at a speed of 27km/hr. find the time taken by it to cross a tunnel of length seven and half kilometres
Penny Nom lui répond.
The Pythagorean theorem 2009-06-24
supreet pose la question :
What are some real-world applications of the Pythagorean theorem?
and
How are the Pythagorean theorem and the distance formula related?

Harley Weston lui répond.
Is one Infinity larger than another in the extended real number system? 2009-06-24
Justin pose la question :
Hello there, I was wondering if one infinity is larger than another in the extended real number system (just like in the transfinite ordinals and cardinals with respect to infinite sets) or are all infinities the same size in the extended real number system? Thanks sooo much for answering my question! I greatly appreciate it!

All the Best,

Justin

Robert Dawson lui répond.
An aeroplane flying in a wind 2009-06-02
Maria pose la question :
The aeroplane flies in a wind of speed 50 kph from the direction S80◦W. However, the direction in which it is pointed, and its speed in still air, are such that its resultant speed and direction are 800 kph, and direction N71.6◦E

I need to find the size of the angle between v and vw, in degrees to one decimal place, and find the speed at which the aeroplane would fly if the air were still, to the nearest kph.

It would help me greatly if I could see a diagram illustrating the velocity va that the aeroplane would have if the air were still, the velocity vw of the wind, and the resultant velocity v of the aeroplane (diagram should be in the form of a triangle illustrating how one velocity vector is the sum of the other two)

Thanks

Harley Weston lui répond.
Stones around a pool 2009-06-01
Jessica pose la question :
I am putting a yard pond in and I am trying to find out how many stones I would need for the perimeter.

The pond is 4ft (W) by ft (L) by 1.5ft (D)

Thank You,

Jessica

Penny Nom lui répond.
The dimensions of a rectangle 2009-05-30
Linda pose la question :
A rectangle has a perimeter of 38 feet & an area of 48 square feet. What are the dimensions of the rectangle?
Stephen La Rocque lui répond.
The width of a rectangle 2009-05-19
Stacey pose la question :
If the length of rectangle is fixed at 29 cm, what widths will make the perimeter greater than 82 cm?
Penny Nom lui répond.
4 tan(360/(2n)) 2009-05-18
molly pose la question :
in the formula to find the area of any regular polygon how do you figure out 4tan part of the formula
Penny Nom lui répond.
Driving to school and back 2009-05-17
marylyne pose la question :
suppose you are late for school and you drive from your house at a constant rate of 70 mph.when class is over, you drive home at a more leisurely 50mph. what is your average speed?
Penny Nom lui répond.
The dimensions of a toy chest 2009-05-07
charlotta pose la question :
My son needs to find the 3 dimensions of a toy chest that has to have a volume of 24 cubic feet can you show how to get the answer
Penny Nom lui répond.
What was her rate of speed? 2009-05-06
Stephanie pose la question :
beth paddled a canoe to a picnic spot in the river in 2 hours. she traveled up the stream back to the original spot in three hours. the current was two miles per hour. What was her rate of speed?
Robert Dawson and Stephen La Rocque lui répond.
Rectangular prisms 2009-05-01
deborah pose la question :
Could you please tell me some examples of different objects in the real world of rectangular prisms?
Harley Weston lui répond.
Two airplanes are 300 miles apart 2009-04-22
afzalsultan pose la question :
Two airplanes are 300 miles apart and flying directly towards each other.One is flying at 200 miles per hour, and the other at 160 miles per hour.How long will it take for the two planes to meet
Robert Dawson lui répond.
The center of an ellipse 2009-04-21
Nae pose la question :
what is the ellipse center of 5x^2+3y^2=15
Stephen La Rocque lui répond.
Volume of a prism 2009-04-21
David pose la question :
The base of a rectangular prism has an area of 15.3 square inches and a volume of 185.13 cubic inches. Write an equation that can be used to find the height "h" of the prism
Robert Dawson and Stephen La Rocque lui répond.
A perpendicular line in standard form 2009-04-21
Kristy pose la question :
Can you help me with this equation? Find the equation, in standard form of the line perpendicular to 2x-3y=-5 and passing through (3,-2) With the equation in standard form with all integer coefficient.
Stephen La Rocque lui répond.
Two similar rectangles 2009-04-19
Alyssa pose la question :
The ratio of the lengths of corresponding sides of two similar rectangles is 3:5. the small rectangle has an area of 36 square centimeters. What is the are of the large rectangle?
Penny Nom lui répond.
Passing three cars 2009-04-16
Larry pose la question :
If 3 cars are going 50 mph, and a fourth car pass the first 3 cars in 200 feet, how fast is the fourth car going?
Stephen La Rocque lui répond.
A man travels a total of 8km in 6 hours 2009-04-10
Kieran pose la question :
Hello!

I was wondering if you could help me with this question! Thank you

A man travels a total of 8km in 6 hours

if his speed was xkm/4hours in the first stage
then his speed was 8-x/2hours in the second part.

If the average speed for the first leg of the journey was 1.1km/h faster than the second part: find x

Penny Nom lui répond.
How many miles per hour was it traveling? 2009-04-04
Regina pose la question :
a car traveled 16 miles in 30 minutes. How many miles per hour was it traveling?
Penny Nom lui répond.
310,000 cubic yards of concrete 2009-03-31
Mary pose la question :
I am interested in getting a good, general analogy for 310,000 cubic yards of concrete - ideally as a length (miles) or distance between two US cities. Thanks!
Penny Nom lui répond.
A trip at two different speeds 2009-03-28
A student pose la question :
Good afternoon!

An automobile travels 4 hours at an average speed of 42MPH. How much longer must the truck travel at an average speed of 55MPH so the average speed for the total trip will be 50MPH?

Thank you for your assistance!

Penny Nom lui répond.
The speed of a tire in revolutions per minute 2009-03-28
Jules pose la question :
Suppose that a tire on a car has an outer diameter of 2,5 feet. How many revolutions per minute does that tire make when the car is travelling 60 miles per hour? (hint:first find the angular velocity in radians per minute.)
Harley Weston lui répond.
Subdividing a four-sided lot 2009-03-27
kannan pose la question :
i have a 1.5 acre land having four sides
A-B=64.8 meters
B-C=94.2 meters
C-D=54.4 meters
D-A=127.2 meters
angle at D is 90
the side AB (frontage)is road facing i want to split the plot in to two halves having same almost area and almost equal frontage, kindly help me, if possible explain with drawing.

Regards
Kannan

Harley Weston lui répond.
A 5 ounce object traveling at 60 mph 2009-03-27
James pose la question :
if a 5 ounce object traveling at 60 mph at 100 feet above the ground, how far will it travel forward before hitting the ground.
Robert Dawson lui répond.
Depth to height ratio 2009-03-26
Janet pose la question :
Is there a formula to determine how deep something (a cabinet) should be based on how tall it is?
Robert Dawson lui répond.
The rate of change of the volume of a sphere 2009-03-25
Kaylin pose la question :
why the rate of change of volume of a sphere is not constant even though dr/dt is constant?
Walter Whiteley lui répond.
Z-score 2009-03-25
Barb pose la question :
I am having trouble finding information on a z score and the conversion to the number of standard deviations a z value can be away from the mean. What exactly does that mean and what am I looking for? Help Please.
Harley Weston lui répond.
A 1.5:1 rectangle 2009-03-23
melody pose la question :
I have an origami model that says to use a 1.5:1 rectangle. I don't understand how to calculate the size of paper I need to use. Surely there is a formula to calculate this ratio? Thanks for your help.
Penny Nom lui répond.
A rectangular open box 2009-03-21
tina pose la question :
An open box is to be made from a rectangular piece of tin by cutting two inches squares out of the corners and folding up the sides. The volume of the box will be 100 cubic inches. Find the dimensions of the rectangular piece of tin.
Stephen La Rocque lui répond.
The perimeter of a rectangle 2009-03-18
marylyne pose la question :
the perimeter of the rectangular is 70 meters. if the width is 40% of the length, find the dimensions?
Penny Nom lui répond.
Water drains from a conical tank 2009-03-11
Tyler pose la question :
Water drains from a conical tank at the rate of 5ft/min^3. If the initial radius of the tank is 4' and the initial height is 10'.
a) What is the relation between the variables h and r? (height and radius)
b) How fast is the water level dropping when h=6'?
Thanks for the help, i'm stumped.

Penny Nom lui répond.
A common tangent to two curves 2009-03-02
Jay pose la question :
For what values of a and b will the parabola y = x^2 + ax + b be tangent to the curve y = x^3 at (1,1)?
Penny Nom lui répond.
Two racers going around a track 2009-02-26
larisa pose la question :
One racer makes a complete trip around the track every 28 seconds, while the other racer completes a trip around the track every minute. How many times will the first racer pass the second racer in 30 minutes?
Robert Dawson lui répond.
A rectangular prism 2009-02-25
Christina pose la question :
I am trying to find the area of the base of a rectangular prism where one cube=_1 cu in. The Answer is given in square inches. I also need the volume of the prism in cu in. For example length=3, w=2, h=5
Penny Nom lui répond.
Fred in his canoe 2009-02-21
Susan pose la question :
Fred paddled for 4 hours with a 7 km/hr current to reach a campsite. The return trip against the same current took 9 hr. Find the speed of Fred's canoe in still water. (Remember to include correct units)
Penny Nom lui répond.
How long will it take Jake to catch up? 2009-02-20
Rebecca pose la question :
John is walking 2 miles per hour. Jake leaves home 15 minutes later and is walking 5 miles per hour . How long will it take Jake to catch up ?
Penny Nom lui répond.
Joggong in opposite directions 2009-02-19
Mallory pose la question :
Emma and her mother jog along a mile-long circular path in opposite directions. They begin at the same place and time. Emma jogs at a pace of 4 mi/h, and her mother runs at 6 mi/h. In how many minutes will they meet?
Robert Dawson lui répond.
The surface area of a cube and rectangular prism 2009-02-16
Mhiko pose la question :
how to derived the total surface area of a cube and rectangular prism using geoboard??
Robert Dawson lui répond.
Solid figures 2009-02-10
Rebecca pose la question :
I need to know the names of solid figures. I have several pictures that I need to answer what type they are. Thanks, Rebecca 3rd grade
Penny Nom lui répond.
A rectangular park 2009-02-06
Debbie pose la question :
A park named Writer's Rectangle opened in town. When asked about the dimensions of the rectangle, the city planner, responded with these clues: ---The diagonals of the rectangular park plus its longer sides together measure seven times one of the shorter sides. ---The length of one diagonal is 250 m longer than one of the shorter sides. Use this information to find the area of the park.
Stephen La Rocque lui répond.
Catching up to the car ahead 2009-02-06
Ashley pose la question :
Car A passes Car B on a freeway. The driver of Car B decides to speed up to 75 mph and catch Car A, whose driver is maintaining a constant speed. Looking ahead, the driver of Car B sees Car A go under an overpass one-qarter mile up the road. Exactly six minutes later, Car B catches Car A. How fast was the car going?
Penny Nom lui répond.
A point on -8x^2+5xy+y^3=-149 2009-02-04
Vivian pose la question :
Consider the curve defined by -8x2+5xy+y3=-149
a) find dy/dx
b) Write an equation for the line tangent to the curve at the point (4,-1)
c) There is a number k so that the point (4.2,k) is on the curve. Using the tangent line found in part b), approximate the value of k.
d) write an equation that can be solved to find the actual value of k so that the point (4.2,k) is on the curve
e) Solve the equation found in part d) for the value of k

Harley Weston lui répond.
Simultaneous equations with an xy term 2009-02-01
angelee pose la question :
xy+5x-2y-10=0 2x+y=1
Penny Nom lui répond.
The amount of concrete in a football stand 2009-01-30
jacques pose la question :
A football stand 150 yd long has 20 tiers of seats; each tier has a rise of 2ft and tread of 3ft.Its construction of reinforced concrete with a cross section as shown. Find the amount of the material used in its construction.
Penny Nom lui répond.
Find area of the rectangle in terms of L. 2009-01-27
Arlen pose la question :
The length of a rectangle is L. The width is 8 less than the length. Find area of the rectangle in terms of L.
Penny Nom lui répond.
How long will it take to make 50 miles? 2009-01-26
Tamara pose la question :
An object is traveling at a speed of 45 km/minute. How long will it take to make 50 miles?
Robert Dawson and Stephen La Rocque lui répond.
A cubical tank that is 8 m on a side 2009-01-25
gina pose la question :
Suppose one edge of a cubic tank is 8m; Find the volume of the tank in cubic meters
Penny Nom lui répond.
Two tangent circles 2009-01-23
Murtaza pose la question :
Two circles touch externally at T. A chord of the first circle XY is produced and touches the other at Z. The chord ZT of the second circle, when produced, cuts the first circle at W. Prove that angle XTW = angle YTZ.
Robert Dawson and Chris Fisher lui répond.
A cyclic quadrilateral 2009-01-23
Murtaza pose la question :
Line ATB touches a circle at T and TC is a diameter. AC and BC cut the circle at D and E respectively.Prove that the quadrilateral ADEB is cyclic.
Robert Dawson and Chris Fisher lui répond.
1 foot drop every 25 feet 2009-01-22
jerry pose la question :
1 foot drop every 25 feet what is the angle of the degree
Penny Nom lui répond.
A tortoise and a hare 2009-01-20
jenna pose la question :
A tortoise can run with a speed of 0.14 m/s, and a hare can run 20 times as fast. In a race, they both start at the same time, but the hare stops to rest for 1.0 minutes. The tortoise wins by a shell (25 cm).
(a) How long does the race take?

(b) What is the length of the race?

Stephen La Rocque lui répond.
The number of gallons in a tank 2009-01-19
Jim pose la question :
Hi, i need to know how many gallons of water can fit into our tank, and how to do the calculations my self. The tank is 72" round by 72" long, i would like some help. Thanks Jim.
Harley Weston lui répond.
The dimensions of a pool 2009-01-18
denise pose la question :
a rectangular swimming pool is three times as long as it is wide. if the perimeter of the pool is 320 feet, what are its dimensions
Penny Nom lui répond.
Fuel in a tank 2009-01-16
Steve pose la question :
I am not a math expert and want help seeing how much fuel is in a tank at one given time the tank that i have is 27 inches round. It is 69 inches long. laying length ways. it holds 140 gallons of fuel at fill up. I do know that it would hold less at the bottom of the tank an more in the center. Is there anybody that could just give me the figures by the inch without a formula. thanks for your time
Stephen La Rocque lui répond.
Parallel distances from arc of circle to its chord 2009-01-16
Roger pose la question :
Give the length of a chord of a circle and the height of the arc, how do I find the lengths of equally spaced parallel lines drawn from the chord to the arc. (Think of the lengths of vertical slats in an arch-topped bed head board.)
Chris Fisher and Stephen La Rocque lui répond.
A rectangular prism 2009-01-13
nika pose la question :
How many bases does a rectangular prism have? What are they?
Harley Weston lui répond.
Two trains 2009-01-12
Shanise pose la question :
If train A leaves the train station at noon traveling 45mph and train B leaves the train station at 1pm traveling 65mph, what time will the trains meet?
Robert Dawson lui répond.
A stack of rectangles 2009-01-11
ashwani pose la question :
Could you please advise the area of a rectangles pyramid. There are 5 rectangles placed one above the other. The top most rectangle has length 2 cm and height 2 cm. The subsequent rectangles length is increased by 1 cm on both the sides, while the height of the 2nd and 3rd rectangle is 2cm each, while the 4th & 5th has a height of 3 cm each. Could you please let me know the the area of the figure and the formula to calculate
Penny Nom lui répond.
Constants, and coeficiants 2009-01-10
Kelsey pose la question :
I am having trouble trying to remember what like terms, constants, and coeficiants are. My math teacher hasent been explaining it very well and i was wondering how to remember what they are, and what they are? I dont understand the concepts.
Stephen La Rocque lui répond.
Two rectangular plots have the same area 2008-12-23
Jason pose la question :
Two rectangular plots have the same area. The first has a perimeter of 40m while the second has a length 2m less than the first and a width 1m greater. Find the length and breadth of the first rectangle
Stephen La Rocque lui répond.
A standard bill on a highway 2008-12-19
Stephanie pose la question :
A standard bill on a highway has a perimeter of 14 feet. the length of the bill board is 6 feet greater than triple the width. What is the length? what is the width?
Robert Dawson and Penny Nom lui répond.
A rectangle with diagonal 8.5 inches 2008-12-14
nekasia pose la question :
what is the area of a rectangle with a diagonal of 8.5 inches PLEASE SHOW WORK
Penny Nom lui répond.
The sides of a rectangle 2008-12-08
Mitchell pose la question :
The perimeter of rectangle ABCD (represented on a Cartesian plane) is 52cm. The equation associated with segment AD is 3x+4y-60=0 Point C is at (18, 14). What is the length of segment AD?
Penny Nom lui répond.
3 equidistant points 2008-12-01
Damien pose la question :
How do you find 3 equidistant points (C,D,E) on a line between point A(Xa, Ya) and point B(Xb, Yb) so that AC, CD, DE and EB are all equal?
Chris Fisher lui répond.
Two tangent circles and common tangents 2008-12-01
Alan pose la question :
Radius of big circle 30cm, radius of small circle 10 cm. From the diagram, the radius from the tangent do not form a semicircle but at an angle. Find the perimeter of the band around both the circle. May need to use trigonometry to find reflex angle AOB, CMD and get the major arc length AB and minor arc length CD
Penny lui répond.
Two tangents to a circle 2008-11-26
rogerson pose la question :
The length of the tangent to a circle is 15 cm. If the angle between the two tangent lines to the circle is 28 degrees, what is the radius of the circle?
Penny Nom lui répond.
Tan(3x) 2008-11-23
Evan pose la question :
Derive an expression for tan3x in terms of tanx
Harley Weston lui répond.
Sigma in a normal distribution 2008-11-18
Justin pose la question :
Suppose the random variable Y can be described by a normal curve with Mu=40. For what value of the standard deviation is P(20 less than or equal to Y less than or equal to 60) = 0.50

-Justin

Harley Weston lui répond.
How far are the boats apart? 2008-11-14
dom pose la question :
Two boats leave port at the same time. They leave at 150 degree angle. One boat travels at 10mph and the other at 20mph. After two hours how far are the boats apart?
Penny Nom lui répond.
The dimensions of a rectangle 2008-11-07
laela pose la question :
A rectangle is 8 feet long and 6 feet wide.If the dimension is increased by the same number of feet,the area of the new rectangle formed is 32 square feet more than the area of the original rectangle.By how many feet was the each dimension increased?
Penny Nom lui répond.
A circle tangent to a line and with its centre on another line 2008-11-01
liza pose la question :
Find the equation of the circle of radius squareroot 26 tangent to the line 5x+y=13 and having its center on the line 3x+y+7=0.
Chris Fisher lui répond.
The speed of the boat and the river 2008-10-28
Jenn pose la question :
On the Amazon River in Brazil, a boat goes 50 miles upstream in 3 hours, later the boat returns to the starting point in 2 hours. What is the speed of the boat in still water and what is the current speed in this part of the Amazon?
Penny Nom lui répond.
Three congruent rectangles 2008-10-27
Meagan pose la question :
Here is my problem: Three congruent (non-square) rectangles are placed to form a larger rectangle. [Two are oriented the same way and the "stacked" while the third is rotated 90 degrees and placed next to the other two.] The total area is 1350 square cetimeters. Square ABCD is then created that has the same perimeter as the large rectangle that was created. E is the midpoint of line CD and F is the midpoint of BC. Find the area of triangle AEF.
Penny Nom lui répond.
Tangent line 2008-10-27
Maddie pose la question :
Find a general equation for a line that touches, but does not pass through the function Y=X2(X squared) + BX+C.
Stephen La Rocque and Victoria West lui répond.
The length of a rectangle is 6 inches less than 3 times its width. 2008-10-26
Angela pose la question :
The length of a rectangle is 6 inches less than 3 times its width. Find the dimensions of the rectangle if its area is 45 square inches.
Penny Nom lui répond.
Two tangent lines to a parabola 2008-10-26
Marcus pose la question :
Show that the tangent lines to the parabola y = ax^2 + bx + c at any two points with x-coordinates p and q must intersect at a point whose x-coordinate is halfway between p and q.
Penny Nom lui répond.
The height of a tank 2008-10-26
Kyle pose la question :
If a water tank holds 750 cubic meters of water and it is 15 metres long and 10 metres wide how many meters tall is it ?
Penny Nom lui répond.
The amount of diesel fuel in a tank 2008-10-26
Mike pose la question :
I have an cylinder shaped oil tank that holds approx. 283 gals of diesel fuel. The tank is laying on on its side, (like taking a garbage can and laying it down on its side). What is the formula to calculate how much oil is in the tank at any given time. If the tank was sitting on end it would be easy to figure out, but it is not.
Stephen La Rocque lui répond.
The slope of a tangent line 2008-10-18
Amanda pose la question :
If f(x)=square root of (x+4), and the slope of the tangent line at x=21 was 1/n for some integer n, then what would you expect n to be?
Stephen La Rocque lui répond.
Travelling home o the train 2008-10-18
nadha pose la question :
MELISSA reached the railway station at 9.30am.The distance between the railway station and her hometown was 720 km.At what time would she reach her hometown if the train travelled at an average speed of 120 km/h?
Penny Nom lui répond.
If you are driving 40mph, how long does it take to go 2.5 miles? 2008-10-18
Nathan pose la question :
If you are driving 40mph, how long does it take to go 2.5 miles?
Penny Nom lui répond.
Two equations in two unknowns 2008-10-17
Dushayne pose la question :
Please help me in solving this problem:
a. 3x-4y=32
5x+2y=10

b. 2x+3y=11
4x+3y=10

Penny Nom lui répond.
A tangent line to f(x) = 1/(x - 1) 2008-10-16
Amanda pose la question :
If f(x)=1/(x-1) then what is the slope of the tangent line at x=-2?
Harley Weston lui répond.
Two planes flying in opposite directions 2008-10-16
samantha pose la question :
i don't understand how to do this problem.two jets leave denver at 9:00 am one flying at a speed 50 km/h greater than the other, which is traveling west. at 11:00 am the planes are 2500 km apart. find their speeds.
Penny Nom lui répond.
The dimensions of a rectangle 2008-10-16
cristine pose la question :
the area of a rectangle is 675sq.cm. if the width is 1/3 of the length. find the dimensions of the rectangle....
Penny Nom lui répond.
Finding the Raw Score for a Mean of 0 and Standard Deviation of 1 2008-10-02
Anita pose la question :
A variable Y has a distribution of mean of Y =80 and standard deviation of Y=36. Find the values of A and B for transforming y*=A +BY so that mean of y* =0 and standard deviation of y*=1.
Janice Cotcher lui répond.
The length of a tank 2008-10-01
alex pose la question :
I have a tank which I can only partly see. It is 70cms wide, 45 cm deep and hold 500litres. How long is it?
Harley Weston lui répond.
How many parallel tangents may a circle have? 2008-09-29
Manish pose la question :
how many parallel tangents may a circle have? the text book shows two.but a circle can have infinite tangents.then why not parallel tangents coz theoretically each tangent have a parallel tangnts then no. of parallel tangent a circle may have is equals to half of the infinity i.e. infinity..
Walter Whiteley lui répond.
What is the perimeter of the rectangle? 2008-09-27
Pauline pose la question :
A rectangle has an area of 27 squared inches. the height is 3 times the base What is the perimeter of the rectangle?
Penny Nom lui répond.
The standard form Ax+By=C 2008-09-26
Susan pose la question :
I am having difficulty changing the point-slope form of the equation of the line y-y1=m(x-x1) to the standard form Ax+By=C. You must express A,B,C in terms of the constants m,x1,y1. I have been able to insert numbers and switch easily from the general to the point slope equation, but I am stumped on how to convert it this way.
Penny Nom lui répond.
5 units from (1,2) and 5 units from y-axis 2008-09-26
Shaun pose la question :
Find the points (x,y) in the plane that are 5 units from (1,2) and 5 units from y-axis. I am more interested in the approach, in general terms, than the numerical values.
Penny Nom lui répond.
Parallel Tangents 2008-09-24
manish pose la question :
how many parallel tangents may a circle have? the text book shows two.but a crcle can have infinite tangents.
Janice Cotcher lui répond.
Limit as it Approaches a Constant 2008-09-16
Brooks pose la question :
what is the limit as x approaches 10 for f(x) = sqrt(x-1) = 3 pleeeeeaase help me out here
Janice Cotcher lui répond.
Distance, time and rate 2008-09-11
Pauline pose la question :
During the first part of a trip, a canoeist travels 100 miles at a certain speed. The canoeist travels 25 miles on the second part of the trip at a speed 5 mph slower. The total time for the trip is 5 hrs. What was the speed on each part of the trip?
Penny Nom lui répond.
A tangent to a circle 2008-09-06
Jake pose la question :
Find an equation of the line that is tangent to the circle x^2 + y^2 = 3 at the point (1,√2)
Penny Nom lui répond.
Largest Inscribed Rectangle 2008-09-03
astrogirl pose la question :
find the shape and area of the largest rectangle that can be inscribed in a circle of a diameter a=2
Janice Cotcher lui répond.
A rectangular tank of water 2008-09-02
Angela pose la question :
A rectangular tank is 80 ft long, 30 ft wide, and 20 ft deep. If 100,000 gallons of water were pumped into the tank, what would be the water rise?
Penny Nom lui répond.
The lengths of the sides of a rectangle are in ratio 5:3 2008-08-29
todd pose la question :
the lengths of the sides of a rectangle are in ratio 5:3 the perimeter of the rectangle is 32 cm find the length of each side
Stephen La Rocque lui répond.
Two tangent circles 2008-08-22
Michele pose la question :
A circle of radius 2 is externally tangent to a circle of radius 8, How do you find the length of their common tangent.
Penny Nom lui répond.
Irregular polygon and Circle that Intersects All Sides 2008-08-20
Xetro pose la question :
Hi, Suppose you have an irregular polygon(convex or concave) with n > 3 sides. The question is - Find some circle that will cut(in limiting case - touch) all the sides of that polygon. It doesnt matter how many times it cuts the side(1 or 2), it just have to cut or touch it. How to find such a circle? or how to decide if such circle even exists? What if those segments do not form a polygon but are some arbitrary segments ? Really want to know how to do it................ Thanks a lot.. Regards, Xetro
Janice Cotcher lui répond.
Coefficients, Like Terms, and Constants 2008-08-14
Maddie pose la question :
How Would I Answer This Problem?

  Coefficients Like Terms Constants
3x+7      
4m+(-3n)+n      
6kp+9k+kp-14      
-8y+6ab+7-3ba      
c+2c+c-5c+1      


I Would Really Appreciate It If You Could Help Me
Sincerely,
Maddie

Penny Nom lui répond.
A linear function 2008-08-07
Warren pose la question :
What are the conditions of the numerical coefficients of the standard form Ax+By=C in Linear Function? How will you transform y=square root of 3 x + 1 in standard form Ax+By=C?
Penny Nom lui répond.
The volume of a fuel tank 2008-08-01
G. pose la question :
I have a fuel tank that is 70 inches by 48 inches and 24 inches deep, how many imperial gallons does it hold?
Victoria West lui répond.
Area of triangle formed by three tangent circles 2008-07-31
brian pose la question :
Three circles with radii 3,4 and 5 touch each other. The circles are tangent to each other. What is the area of the triangle formed by the centers of the circles?
Stephen La Rocque lui répond.
Inscribed Rectangle 2008-07-30
Felicia pose la question :
A rectangle whose base is twice its altitude is inscribed in a circle whose radius is 5 mm. Find the area of the rectangle.
Penny Nom lui répond.
Running in opposite directions 2008-07-29
maame pose la question :
if i run six miles per hour and my friend runs four miles per hour and we both run for two hours in opposite directions how many miles apart will we be after the two hours?
Janice Cotcher and Penny Nom lui répond.
Problems understanding math 2008-07-27
Cindy pose la question :
why do so many people have problems understanding math. is it because at some point along the way they didn't fully understand a concept and they then lose confidence. Learning math is cummulative so what you don't learn at one point just gets more confusing as you move along. how do we correct this? how can i help students in junior and senior high who do poorly in math.
Stephen La Rocque and Victoria West lui répond.
Braking Distance Relationship 2008-07-23
Mr.Adjetey pose la question :
you are travelling at 30km/h.According to the rule of thumb,the braking distance is 9 metres when braking normally.How long is the braking distance under the same conditions when travelling at 60km/h?
Janice Cotcher lui répond.
Simultaneous equations 2008-07-23
Franco pose la question :
Solve

3 D + E - F = -10
-2 D - F = -4
-3 D - 4 E - F = -25

Franco

Penny Nom lui répond.
A tangent to a curve through a point not on the curve 2008-07-23
Carter pose la question :
How does one find the tangent points on a curve, given only the curve's function and the x-intercept of that tangent line?
i.e. Find the point(s) on the curve y = -(x^2) + 1, where the tangent line passes through the point (2, 0). I know that there will be two such points, one where y is very close to 1, and the other point where y is a large negative number. However, I do not recall how to figure out the tangent line equation given a single intercept and solving to find the tangent points.

Penny Nom lui répond.
A tangent line to a circle 2008-07-09
Rita pose la question :
The tangent to a circle may be defined as the line that intersects the circle in a single point, called the point of tangency. If the equation of the circle is x^2 + y^2 = r^2 and the equation of the tangent line is y = mx + b, show

r^2(1 + m^2) = b^2

Harley Weston lui répond.
Going from 45 mph to 35 mph 2008-07-09
Terry pose la question :
How long (distance - feet AND time) will it take a car traveling at 45 mph to slow down to a speed of 35 mph?
Harley Weston lui répond.
Two trains 2008-07-07
Elisha pose la question :
Trains at each end of the 50. km long Eurotunnel under the English Channel start at the same time into the tunnel. Find their speeds if the train from France travels 8. km/h faster than the train from England and they pass in 17 minutes.
Janice Cotcher and Penny Nom lui répond.
A boat travels 20 kms upstream in 6 hrs ... 2008-07-07
vidya pose la question :
A boat travels 20 kms upstream in 6 hrs and 18 kms downstream in 4 hrs. Find the speed of the boat in still water and the speed of the water current?
Penny Nom lui répond.
Fit 7 different rectangles on grid paper 2008-07-02
anonomous pose la question :
I need to fit 7 different rectangles on grid paper of 1cm squared. Each squared centimetre equals 4 squared metres, and it needs to end up as area 64 square metres.
Janice Cotcher lui répond.
A rectangular room 2008-06-30
Peter pose la question :
A rectangular room has a perimeter of 42 feet and an area of 108 square feet. What is the length, in feet, of the shorter side?
Penny Nom lui répond.
A rectangle 2008-06-26
SEBASTIAN pose la question :
How to arrange quadrilateral in the form of a rectangle?
Penny Nom lui répond.
Two forces acting on a body 2008-06-21
Rita pose la question :
Before answering the question below, what exactly is, in basic words, resultant force? QUESTION: Two forces of 50 and 68 pounds act on a body to produce a resultant force of 70 pounds. Find, to the nearest 10 minutes or nearest tenth of a degree, the angle formed between the resultant force and the smaller force.
Harley Weston lui répond.
How far from each other will they be? 2008-06-18
kerstin pose la question :
a women jogging at 6 mi/h passes a men biking in the opposite direction at 12 mi/h. if the maintain their speeds, how far from each other will they be 10 minutes after passing?
Stephen La Rocque lui répond.
A space camera circles the Earth 2008-06-16
Rita pose la question :
A space camera circles the Earth at a height of h miles above the surface. Suppose that d distance, IN MILES, on the surface of the Earth can be seen from the camera.

(a) Find an equation that relates the central angle theta to the height h.

(b) Find an equation that relates the observable distance d and theta.

(c) Find an equation that relates d and h.

(d) If d is to be 3500 miles, how high must the camera orbit above Earth?

(e) If the camera orbits at a height of 400 miles, what distance d on the surface can be seen?

Penny Nom lui répond.
Escort cards on a rectangular table 2008-06-13
Susan pose la question :
What size rectangular table will we need to put 230- 2" X 3.5" escort cards on for my daughter's wedding reception with a spacing of .5 inch between them on all sides? Thanks so much for your help
Penny Nom lui répond.
-2(x - 1)^2 + 8 2008-06-12
kasondra pose la question :
y=-2(x-1)2[thats a square] +8 that need to be put in standard form
the answer is y= -2x2 -4x + 6
i got y= -2x2 -4x -4
i just don't get how my teacher got that answer

Penny Nom lui répond.
tan(4a - b) 2008-06-12
A student pose la question :
hi guys just a quick help on question needed thanx if tan a = 1/5 and tan b = 1/239 find value of tan(4a-b) thanks alot in advance
Harley Weston lui répond.
The length and width of a rectangle 2008-06-11
gregg pose la question :
the perimeter of a rectangle is 70 feet. the ratio of length to width is 4:3. how would i calculate the length of the height and width?
Penny Nom lui répond.
What are the dimensions of the rectangle? 2008-06-11
Denise pose la question :
A rectangle has a diagonal that is 3.6 feet longer than the length and 7.1 feet longer than the width. What are the dimensions of the rectangle?
Claude Tardif and Victoria West lui répond.
Three mutually tangent circles 2008-06-04
Jacob pose la question :
If three circles are mutually tangent, does that mean that the two tangent lines are perpendicular?
Chris Fisher lui répond.
The area of a rectangle 2008-05-27
Becky pose la question :
the area of a rectangular lot is represented by 6t^2+13t-5. What are the length and the width of the rectangular lot?
Harley Weston lui répond.
The length of a shadow 2008-05-27
Simon pose la question :
A figure skater is directly beneath a spotlight 10 m above the ice. IF she skates away from the light at a rate of 6m/s and the spot follows her, how fast is her shadow's head moving when she is 8m from her starting point? The skater is (almost) 1.6m tall with her skates on.
Stephen La Rocque and Harley Weston lui répond.
Gasoline in a cylindrical tank 2008-05-25
Simon pose la question :
A cylindrical tank with height 15m and diameter 2m is being filled with gasoline at a rate of 500L/min. At what rate is the fluid level in the tank rising?(1L = 1000cm^3). About how long will it take to fill the tank?
Penny Nom lui répond.
How many bricks I can place around a 26-inch circle? 2008-05-22
Jon pose la question :
I want to know how many bricks I can place around a 26-inch circle? There must be a formula other than trial and error. The length of the bricks is 6-inches. [How many 6-inch tangents can be in a 26-inch circle? Thank you very much. Jon
Harley Weston lui répond.
55 mi/h for 4 h 2008-05-21
brenda pose la question :
mary drove her car at 55 mi/h for 4 h. Use the formula d = rt (where d is the distance traveled, r is the rate of travel and t is the time traveled) to determine how far mary traveled.
Penny Nom lui répond.
The sides of a rectangle 2008-05-16
bill pose la question :
The area of the rectangle is 170 sq.ft. the width is unknown and the length is the width plus 7 ft. I set it up like this w(w+7)=170 and this is where I get lost. Thanks, Bill
Penny Nom lui répond.
Fencing around a playground 2008-05-15
Vanessa pose la question :
If the playground is a rectangle with it's width 10ft shorter than it's length, and it can be enclosed by exactly 140ft of fence, what is the length and width of the playground?
Penny Nom lui répond.
A crate is launched from an airplane 2008-05-10
Michelle pose la question :
A crate is launched from an airplane, 75 feet above the ocean, with an initial vertical velocity of 60 feet per second. How many seconds will it take for the crate to hit the water? Round to the nearest hundredth.
Harley Weston lui répond.
How far is it from the top to the bottom of the mountain? 2008-05-09
Matthew pose la question :
A ski lift carries a skier up a slope at a rate of 2 miles per hour. Following the same path down the mountain, the hiker has a rate of 4 miles per hour. If the round trip took 3 hours, how far is it from the top to the bottom of the mountain?
Penny Nom lui répond.
The surface area of a tank 2008-05-09
jack pose la question :
i'm looking for the square footage of a tank that is 10'diameter x 23'high,floor,ceiling and walls
Penny Nom lui répond.
The standard form of an ellipse 2008-04-30
Rebecca pose la question :
I have to write the following equation into standard form of an ellipse:

9(X-1)^2 + (Y+1)^2 = 1

Stephen La Rocque and Harley Weston lui répond.
5 miles per hour for 30 minutes 2008-04-29
Joshua pose la question :
A boat travels at a constant rate of 5 miles per hour for 30 minutes. How far does the boat go in that time?
Penny Nom lui répond.
A rectangle inscribed in a circle 2008-04-27
sridhar pose la question :
A rectangle with perimeter 28 cm inscribed in a circle of radius 5 cm find the area ?
Penny Nom lui répond.
An octagonal prism 2008-04-27
Melanie pose la question :
My son is identifying geometric shapes in the real world? We are stuck on octagonal prism, rectangular prism and square prism. Can you help me out with some examples. Thanks
Penny Nom lui répond.
Driving home from work 2008-04-25
brittanygrant pose la question :
brittany house is 37 miles from his job. He leaves at 6:25pm, and drives 49 miles per hour. what time will he get beck home?
Penny Nom lui répond.
Find the length and the width of the rectangle 2008-04-24
Vickie pose la question :
A rectangle is 2 times longer than it is wide. It has a diagonal length of 50 centimeters. Find the length and the width of the rectangle. Round your answers to the nearest tenth. Show your work.
Penny Nom lui répond.
The dimensions of a rectangle 2008-04-20
Brandy pose la question :
Find the dimensions of a rectangle with a primeter of 54 cm if the length is 5 less than three times the width.
Penny Nom lui répond.
45 miles at 50 mph 2008-04-18
Willie pose la question :
If you travel at 50 mph, how long does it take to go 45 miles?
Penny Nom lui répond.
A solid figure with 3 rectangular faces and 2 triangular faces 2008-04-17
Emily pose la question :
I am in the 3rd grade and my teacher gave us a question. What is a solid figure with 3 rectangular faces and 2 triangular faces?
Penny Nom lui répond.
A tangent to two circles 2008-04-13
erson pose la question :
find the length of the tangent segment AB to two circles whose radii are a and b respectively, when the circles touch each other.

the illustration looks like this...hope you'll understand... there are 2 circles - one is big one is small. they touch each other. and there is this irregular 4 sided polygon that connects them...there is a line that connects them from their center point and another from the tip of the circles...and that's it...i cannot explain very well please bear with me

Stephen La Rocque lui répond.
A tangent to a circle 2008-04-13
rogerson pose la question :
Line t from point P is tangent to circle O at T, the point of tangency. Find the length of PT when the radius of the circle is 5cm and the distance between points P and O is 8cm.
Stephen La Rocque lui répond.
Jill and Matt run on a 400 meter long oval track 2008-04-11
jamie pose la question :
Jill and Matt run on a 400 meter long oval track. Jill and Matt each run 10 laps daily and both run in the same lane. One day Jill and Matt began at the same point, but ran around the track in opposite directions. Jill ran at a constant speed that was 2 meters per second faster than matts constant speed. Jill passed Matt for the first time in 40 seconds. Jill ran at a constant rate of how many meters per second?
Penny Nom lui répond.
Two trains left the city at the same time 2008-04-11
J pose la question :
Two trains left the city at the same time, traveling in opposite directions. The eastbound train travels for ten hours and the westbound train travels for 5 hours. They are now 1300 km apart. The westbound train's rate is 20 km/hr faster than the eastbound train. Find the speed of each train.
Penny Nom lui répond.
A rectangle word problem 2008-04-10
Nick pose la question :
A rectangle is twice as long as it is wide. If the length and width are both increased by 5cm, the resulting rectangle has an area of 50cm^2. Find the dimensions of the original.
Penny Nom lui répond.
A river boat 2008-04-09
jessica pose la question :
heres a crazy riddle a river boat that travels 12 mph in still water makes a pleasure trip to a city upstream and back in 3 hours. If the city is 10 miles aways, what is the rate of the current
Stephen La Rocque lui répond.
The shortest distance from a point to a line 2008-04-03
Katherine pose la question :
How do I find the shortest distance from the point (3,5) to the line x = -2
Stephen La Rocque lui répond.
Perimeter, area and diagonals of a rectangle 2008-04-03
jenea pose la question :
I have to find the perimeter as well as the area of a rectangle when given the diagonals are 12 units long and they intersect at a 60 degree angle. how do i find both the area and perimeter; do i use the 30 60 90 triangle rule?
Stephen La Rocque and Penny Nom lui répond.
The rectangle with smallest perimeter 2008-04-01
nicole pose la question :
when given an area,squares are the rectangles with the smallest perimeter write the length and width of the rectangle with the smallest perimeter
Penny Nom lui répond.
A rectangular prism 2008-03-31
Chanlie pose la question :
i need need to find a rectangular prism with a total surface area of 210 units.
Penny Nom lui répond.
The area of a rectangle 2008-03-25
Raphael pose la question :
What is the area of rectangle that measures 7 yards by 23 yards
Penny Nom lui répond.
Expected value and standard deviation 2008-03-19
Patrick pose la question :
Heres a question i cant figure out:
a small airline company has only three flights per day. The number of delayed flights per day is regarded as a random variable, and I'm supposed to calculate the expected value and standard deviation of the number of delays. the probability distribution looks like:
No. of Delays: 0 1 2 3
Prob. of delay: 05. 0.3 .1 .1

Harley Weston lui répond.
Distance seen 2008-03-18
Nev pose la question :
formule: Distance Seen
S = 1.225 x square root of H
S = Distance seen in Miles
H = Height in Feet


What dose 1.225 Relate To ?

Stephen La Rocque lui répond.
A train and a boat 2008-03-15
Sabrina pose la question :
A railroad bridge is 20m above, and at right angles to, a river. A person in a train travelling at 60 km/h passes over the centre of the bridge at the same instant that a person in a motorboat travelling at 20km/h passes under the centre of the bridge. How fast are the two people separating 10s later?
Harley Weston lui répond.
A fence around a rectangular region 2008-03-06
sharon pose la question :
a farmer want to make a rectangular fence he has 750 feet of material . if the width is 95 feet what is the area of the rectangle
Penny Nom lui répond.
The dimensions of a rectangle 2008-03-06
Julie pose la question :
Find the dimensions of a rectangle with an area of 400. Width x ft. Length (2x-7)ft.
Stephen La Rocque and Penny Nom lui répond.
Two points moving on a straight line 2008-03-06
laura pose la question :
Particle A travels at constant speed of 1.0ms-1 in straight line, passing particle B, at which time particle B beings traveling with constant acceleration of 0.2ms-2 until reaching Particle A.
What equations represent the displacement of particle A and particle B measure from the point they first pass?
How long does it take for particle B to catch up with particle A?
What is the speed of particle B when reaching particle A?
What distance have both particles traveled from where they first pass to where they meet again?
Calculate the displacement of both particle A and B at 2 second intervals between t=0s and t=12s?

Stephen La Rocque and Penny Nom lui répond.
A dog and a fire hydrant 2008-03-06
Brittany pose la question :
A bulldog is walking east along Main St. at a speed of 4 miles per hour. He wants to get to a fire hydrant on a parallel street. Initially, the bearing to the hydrant is south 62 degrees east. After 20 minutes, the bearing is south 41 degrees east. If the bulldog continues his walk, what is the closest he will be to the hydrant?
Stephen La Rocque lui répond.
Is every rectangle a square? 2008-03-04
Odette pose la question :
if every square is a rectangle, is every rectangle aslo a square?
Penny Nom lui répond.
What point on the graph y = e^x is closest to the origin? 2008-03-03
elvina pose la question :
What point on the graph y = e^x is closest to the origin? Justify your answer.
Stephen La Rocque lui répond.
Simultaneous equations 2008-02-29
CONOR pose la question :
I was wondering if you could help me with this problem

7x - 5y = -1
3y = 4x

Penny Nom lui répond.
A package of supplies is dropped from a plane 2008-02-29
beth pose la question :
An airplane flies west at a speed of 200m/s. A package of supplies is dropped from the plane to some campers. if the plane is at an altitude of 1000meters, how far from the campers should the package be dropped to land near them? ignore wind resistance.
Stephen La Rocque lui répond.
Is a square a rectangle? 2008-02-29
Jaime pose la question :
Is a square a rectangle?
Penny Nom lui répond.
The diagonal of a rectangle 2008-02-21
tim pose la question :
is there a formula for finding the diagonal of a rectangle?
Penny Nom lui répond.
The equation of a line 2008-02-17
Jennifer pose la question :
Given the point A(3,2)B(5,8) find the equation of the line AB ( in standard form )
Penny Nom lui répond.
A ball bearing is placed on an inclined plane 2008-02-15
Leah pose la question :
A ball bearing is placed on an inclined plane and begins to roll. The angle of elevation of the plane is x. The distance (in meters) that the ball bearing rolls in t seconds is s(t) = 4.9(sin x)t^2. What is the speed of the ball bearing, and what value of x will produce the maximum speed at a particular time?
Penny Nom lui répond.
The area of a rectangle 2008-02-12
mark pose la question :
The diagonal of a rectangle is 15cm, and the perimeter is 38cm. What is the area? It is possible to find the answer without finding the dimensions of the rectangle. Please help me and show as much of the problem as possible. Thank You
Penny Nom lui répond.
The width of a rectangle is 4 less than twice its length. 2008-02-09
Shawn pose la question :
The width of a rectangle is 4 less than twice its length. If the area of the rectangle is 72 cm, what is the length of the diagonal
Stephen La Rocque lui répond.
The distance around a building 2008-02-06
olivia pose la question :
If you walk around a building that is 102,869 sq ft, how many miles is that?
Penny Nom lui répond.
Two cars are on a collision course 2008-02-06
Danielle pose la question :
Two cars are on a collision course, heading straight towards each other. One car is traveling 45 miles per hour and the other is traveling 75 miles per hour. How far apart will the two cars be one minute before they collide.
Penny Nom lui répond.
The equation of a circle 2008-02-05
aime pose la question :
Find the equation of the circle tangent to 3x+4y-15=0 at P1(1,3) and passing through P2(6,3) and P3(0,5)?
Stephen La Rocque lui répond.
How fast does each travel? 2008-02-05
kRYSTAL pose la question :
May rides her bike the same distance that leah walks. May rides her bike 10km/h faster than leah walks. Its takes May 1 hour and Leah 3 hours to travel the sam distance, how fast does each travel?
Penny Nom lui répond.
The dimensions of a rectangle 2008-02-01
Evan pose la question :
you are given that the area of a rectangle is 21.6in sq. find the base and the height of the rectangle.
Penny Nom lui répond.
Driving from Mathville to Bioville 2008-02-01
Ariel pose la question :
Mahtab took hours to drive from Mathville to Bioville, a total of 485 km. She drove part by highway at 80 km/h and part by slow roads at 30 km/h. How many hours did she drive each type of road?
Penny Nom lui répond.
The standard form of a line 2008-01-30
Thomas pose la question :
I'm attempting to get this in standard form

slope=3;(1,5)

Penny Nom lui répond.
2 km at 5.00 m/s 2008-01-29
Stephanie pose la question :
How much time does it take for a student running at an average speed of 5.00 m/s to cover a distance of 2.00 km?
Penny Nom lui répond.
How far from the corner will the police catch the car? 2008-01-27
Joel pose la question :
A car is going down the road at a speed of 90km/h in a 50km/h zone. As the car passes a corner, a police cruiser sitting there notices it. Five seconds later the cruiser begins accelerating at 5.0m/s squared. Assuming that he is able to maintain this acceleration, how far from the corner will the police catch the car? How fast will the cruiser be going?
Stephen La Rocque lui répond.
The volume of a tank 2008-01-27
Fred pose la question :
A cubic tank holds 1,000 kilograms of water what are the dimensions of the tank in meters?
Harley Weston lui répond.
The standard form of a line 2008-01-24
James pose la question :
I need to put it in Standard from ax+by=c the problem is (-4,0); parallel to y=-2+1 how can I put this in Standard from
Stephen La Rocque lui répond.
The equation of a line 2008-01-20
Sara pose la question :
The question is:

Write the equation of a line that is parallel to y=3x-2 through the point (-5,9). I think the correct equation for this is y=3x+24. But I have to write it in standard form, and I can't seem to figure out how to do that. Please answer soon! Thanks!

Stephen La Rocque and Penny Nom lui répond.
Two circles in a rectangle 2008-01-18
Alex pose la question :
One side of a rectangle is 10 and the other is x.

Two circles with equal radii are inscribed in the rectangle and like a Venn Diagram, the circles overlap.

Each circle touches the top and bottom of the rectangle and the left circle touches the left side of the rectangle and the right circle touches the right side of the triangle.

The distance between the centre of each circle is 2x/3.

Find x

Penny Nom lui répond.
Two bikers race on a circular track 2008-01-17
Abby pose la question :
Two bikers race on a circular track. Biker A can circle the track in 8 minutes, and Biker B can circle the track in 6 minutes. From the start of the race, how many minutes will it be before Biker B overtakes Biker A?
Stephen La Rocque and Penny Nom lui répond.
Driving towards each other 2008-01-16
Shanda pose la question :
Paul and Charlene are 420 miles apart. They start toward each other with Paul driving 16 miles per hour faster than Charlene. They meet in 5 hours. Find Charlene's speed.
Stephen La Rocque lui répond.
The distance back to school 2008-01-16
priya pose la question :
a boy starts travelling from his house to his school. He travels 1 km east and then 2km north and then 1 km East and 1km North and then 1 km east and then 1 km North. find out the shortest distance for him to reach his shool?
Harley Weston lui répond.
Hoisting an anchor 2008-01-10
ron pose la question :
four men on a boat are using a capstan for hoisting an anchor weighing 2000lbs. The diameter of the barrel of the capstan at the section in use is 8in., and the pull on the chain carrying the anchor and passing around the capstan barrel is assumed to act at a distance of 1in. from the surface of the barrel. If the distance from the axis of the barrel to each point at which effort is applied to a capstan bar is 40in., what force must be applied by each man hoisting the anchor?
Stephen La Rocque lui répond.
How fast does Kim paddle in still water? 2008-01-07
Fran pose la question :
Kim paddled a canoe 10 km upstream and then paddled back to his starting point. If the rate of the current was 2 km/h that day and the whole trip took 3.75 h, how fast does Kim paddle in still water?
Penny Nom lui répond.
What is the speed of the plane in still air? 2008-01-05
oscar pose la question :
A plane flies 400 miles with the wind and 340 miles against the wind in the same length of time. If the speed of the wind is 24mph, what is the speed of the plane in still air?
Penny Nom lui répond.
The shortest distance to a line 2008-01-04
nana pose la question :
3y+4x-12=0 is the equation of the line AB on a graph......the line AB joins both y and x axises together.....point A is on y axis and its value is 3....point B is on x axis and its value is 4.....Question : from point O(0,0).find the point ont the line AB
Stephen La Rocque lui répond.
A tangent to a circle 2008-01-04
adam pose la question :
Find a>0 so that the line y=x+a is a tangent to the circle x^2 +y^2=2.
Stephen La Rocque and Harley Weston lui répond.
Lining up coins visually using geometry and trigonometry 2007-12-31
Jessica pose la question :
a) In what order would you arrange a penny, a nickel, a dime, a quarter, and a half-dollar so that they all have the same apparent size? The diameters of the coins, in thousandths of inches, are as follows: penny, 750; nickel, 835; dime, 705; quarter, 955; half-dollar, 1205.
b) How should the coins be placed, if the distance between the dime and the half-dollar is 100 units? How far from thw dime should your eye be to see that all the coins have the same apparent size?
c) What angle do the coins subtend when they have the same apparent size?

Stephen La Rocque lui répond.
A rectangle is three times as long as it is wide. 2007-12-31
Robert pose la question :
A rectangle is three times as long as it is wide. If the length is decreased by 2 cm and the width is increased by 3 cm, the new rectangle has an area of 42 cm. What are the dimensions of the original rectangle?
Penny Nom lui répond.
The surface area of the rectangular solid 2007-12-30
Sara pose la question :
For my math homework i found the volume of a rectangular solid whose deminsions were in feet and the numbers were 10 by 20 by 30
10 = hight
20 = short side base
30 = long side base
and now i have to find the surface area of the rectangular solid....
i know how to do this but i can't get the right answer it should be 2,200 ft squared but i keep getting 13,00 feet squared

Penny Nom lui répond.
The standard normal distribution 2007-12-29
GEORGE pose la question :
Statistics texts state that in a normal distribution, 1 standard deviation covers 68%, 2SD 95% 3SD 99.7%. However, on looking at the tables for normal curve areas, the percentage for a z value of 1 is 84.13. 68 % of values are covered at a z value of 0.47. The discrepancies exist even for other values but are smaller. So why is the rule of thumb so different from the Table for Normal Curve areas?
Harley Weston lui répond.
Sally, Charlie and Snoopy in a race 2007-12-29
Marie pose la question :
Sally and Charlie are having a race. Charlie gets a 900 foot lead and runs 8 inches per second. Sally begins at the starting line and runs at a rate of 5 ft per second. Charlie's dog is also in the race. Snoopy starts 1100 feet ahead of Sally and runs toward the starting line at a rate of 1 foot per second.

When will Charlie and Snoopy past each other and how far will they be from the starting line?

Penny Nom lui répond.
Two cars drive in opposite directions 2007-12-23
dale pose la question :
2 cars starting from the same point in opposite direction on a straight highway drove 6 miles then turn left and drove 8 miles. How far apart are the cars?
Penny Nom lui répond.
The dimensions of a rectangle 2007-12-22
Justin pose la question :
I'm trying to find the width of a rectangle. I have its area and its height. The area is 32 inches square and the width is 4 feet (48 inches). Can someone help explain this to me?
Penny Nom lui répond.
A triangle and a rectangle 2007-12-14
Someone pose la question :
A certain triangle has sides that are, respectively, 6inches, 8inches, and 10 inches. A rectangle with a n area equal to that of the triangle has a width of 3 inches. What is the perimeter of the rectangle, in inches.
Penny Nom lui répond.
The dimensions of a rectangle 2007-12-12
tara pose la question :
The length if a rectangle is 5 feet less than twice its width. The perimeter of the rectangle is 38 feet. let w represent the width. write an equation for the perimeter of the rectangle in terms of w. Then solve the equation to find the length and width o the rectangle.
Penny Nom lui répond.
The tangent to a curve 2007-12-10
Christy pose la question :
I know this question is simple but I can't figure out what I'm doing wrong.
Find the equation of the tangent line to the curve 2x^2 - y^4= 1 at the point (1,1).

Penny Nom lui répond.
Mean and standard deviation 2007-12-10
Jamie pose la question :
Let n be any odd whole number.
a) Which has the greater mean: the odd whole numbers from 1 to n, or the even whole numbers from 2 to n-1?
b) Which has the greater standard deviation: the odd whole numbers from 1 to n, or the even whole numbers from 2 to n-1?

Penny Nom lui répond.
A triangle and a pentagon 2007-12-08
Olivia pose la question :
A regular pentagon has an area of 800 square centimetres. What is the area of the triangle extended from one side of the pentagon?
Stephen La Rocque lui répond.
System of equations 2007-12-06
Jenn pose la question :
change the equation,x-y=4 to form y=mx+b the solution to the system of equations y=2x and y=-x+3 is
Stephen La Rocque lui répond.
Chicken and goat feet 2007-12-05
Kim pose la question :
Old McDonald raises goats and chickens. The animals have a total of 100 heads adn 360 feet. How many goats and how many chickens does Mr. McDonald have?
Stephen La Rocque and Penny Nom lui répond.
Two cars going in opposite directions 2007-11-25
alexa pose la question :
two cars leave town at the same time going opposite directions. one of them travels at 55 mph and the other at 65 mph. in how many hours will they be 150 miles apart?
Penny Nom lui répond.
The maximum area of a rectangle 2007-11-23
Christy pose la question :
Question from Christy, a student:

Show that among all rectangles with an 8m perimeter, the one with the largest area is a square.

I know this is simple but I'm not sure if I'm doing it correctly. Here is what I did.

1. A = xy
2. 8 = 2x+2y
3. y = 4-x
4. A = x(4-x) = 4x-x^2


Not sure what to do from this point because I don't know if its right.

Harley Weston lui répond.
A t-test 2007-11-20
Rachel pose la question :
I am wanting to use the t-test to find if temperature over a period of 5 days was significantly different to the mean temperature for that time of year. So i want to compare expected temps to actual temps. The problem is that because the expected temperature is the same for the 5 days it gives me a standard deviation of zero. Does this mean the t-test cannot be used because the f-test can't be calculated. If so is there an alternative test?
Harley Weston lui répond.
Standard deviation 2007-11-20
Shahzada pose la question :
when and why we use standard deviation in Data analysis?
Harley Weston lui répond.
A rectangular prism 2007-11-16
nicholas pose la question :
What is the height the surface area to a rectangular prism with a volume of 350 milliliters?
Stephen La Rocque lui répond.
A cylindrical tank 2007-11-16
Mario pose la question :
I want to determine how many gallons i have inside a cylinder (tank) that is resting on its side (the Height), NOT standing up. I know V=pi x r2 x H. And 1 cubic foot = 7.48 gallons. Here are the dimensions r=2' H=20'. Now my question is how do I determine how much liquid i have inside, if the level of the liquid is about 1/2 of the way of its Diameter (in other words 2'). Remember this cylinder is lying on its side.
Penny Nom lui répond.
A particle moves in the xy-plane 2007-11-12
Russell pose la question :
A particle moves in the xy-plane with

X = 2t^3 - 12t^2 + 18t

Y = 3t^4 - 28t^3 + 72t^2

find an equation of the line tangent to the given curve at t_0_ = 1

note: t_0_ is t subscript 0

Harley Weston lui répond.
Stopping distance and speed 2007-11-11
Joanna pose la question :
The algebraic relation d=0.0056^2 ++ 0.14s models the relation between a vehicle's stopping distance d, in metres, and its speed s, in kilometres per hour.
(a) What is the fastest you could drive and still be able to stop within 80 m?
(b) What is the stopping distance for a car travelling at 120 km/h?
(c) Estimate the length of an average car. How many car lengths does the the stopping distance in (b) correspond to?

Stephen La Rocque lui répond.
The width of a rectangle 2007-11-07
BJ pose la question :
The perimeter of a rectangular field is yards. If the length of the field is yards, what is its width?
Penny Nom lui répond.
Two cars 2007-11-04
Jalisa pose la question :
If Car "A" is traveling 50 miles per hour and car "B" is traveling 60 miles per hour, how long will it take car "B" to catch up to car "A" if car "A" had a 15 mile head start.
Penny Nom lui répond.
Constantly accelerated motion 2007-10-29
Priyanka pose la question :
A, B and C are three points lying in that order on a straight line. A body is projected from B towards A with speed 3 m/s. The body experiences an acceleration of 1 m/s^2 towards C. If BC =20 m, find the time taken to reach C and the distance travelled by the body from the moment of projection until it reaches C.
Stephen La Rocque lui répond.
A car traveled 175m at certain speed 2007-10-28
abdi pose la question :
A car traveled 175m at certain speed. if the speed had been 20 mph faster, the trip could have been made in 1 hr less time. find the speed?
Stephen La Rocque lui répond.
How to solve related rates problems 2007-10-27
David pose la question :
Can you plz explain how and where you come up with an equation to solve this?
Find the rate of change of the distance between the origin and a moving point on the graph of y = sin x if dx/dt = 2 centimeters per second.

Stephen La Rocque lui répond.
Area of a triangle formed by three points on a graph 2007-10-26
Betty pose la question :
My question is 'find the are of a triangle whose vertices have coordinates (3,5),(6,-5), and (-4,10)
Stephen La Rocque lui répond.
The length of a rectangle is twice the width 2007-10-26
Tami pose la question :
The length of a rectangle is twice the width. The number of square units in it's arear is four times the number of units in it's perimeter. What are the dimensions of the rectangle?
Penny Nom lui répond.
Given a six by six square, how rectangles are there in the square? 2007-10-24
Maria pose la question :
Given a six by six square, how rectangles are there in the square?
Stephen La Rocque lui répond.
The length of a rectangle 2007-10-24
Kharez pose la question :
What is the length of a rectangle with an area of 24 square feet and a width of 4 feet?
Penny Nom lui répond.
Stanley Cup costume (truncated cone pattern) 2007-10-19
Janet pose la question :
You hockey fans will love this question. I am making a Stanley Cup halloween costume and need a flat pattern for the bowl portion. I believe a truncated cone will work nicely. Base circumference needs to be 32" (10.19 diameter). Top circumference needs to be 44" (14 diameter). It needs to be 8" high. Thanks for your help.
Stephen La Rocque lui répond.
Calculate the dimensions of the rectangle 2007-10-16
Sara pose la question :
The perimeter of a rectangle is 62cm. The length of the diagonal is 25 cm. Calculate the dimensions of the rectangle.
Stephen La Rocque lui répond.
Four triangles in a square 2007-10-15
Kristina pose la question :
A square with side lengths of 6 cm is divided into 3 right triangles and a larger isosceles triangle. If the three right triangles have equal area, find the exact area of the isosceles triangle.
Stephen La Rocque lui répond.
The dimensions of a rectangle 2007-10-14
Elizabeth pose la question :
The perimeter of a rectangle is 20m. The area is 20sqm. Calculate the dimensions of the rectangle. Give your answers correct to two decimal places.
Penny Nom lui répond.
Substitution method 2007-10-11
Kevin pose la question :
3xx+2y=-36-y=11
Stephen La Rocque lui répond.
Grouped data 2007-10-08
Nimra pose la question :
The following sets of data represent the distributions of
house prices in the north-east and south-west of a country.
Random samples of 100 houses were selected in each region.
(a) Calculate the mean, median and standard deviation for

Harley Weston lui répond.
Coin jar 2007-10-07
a student pose la question :
Sally empties his jar of coins. It contains $3.75 in nickels, dimes, and quarters. The number of dimes is twice the number of nickels and the number of quarters is three less than the number of nickels. Determine how many nickels, dimes, and quarters were in the in the jar.
Stephen La Rocque lui répond.
Solving four simultaneous equations (system of four linear equations) 2007-10-07
Johan pose la question :
I need some help in solving this question
x + 2y - 3z + 4w = 12
2x + 2y - 2z + 3w = 10
0 + y + z + 0 = -1
x - y + z - 2w = -4

Stephen La Rocque lui répond.
Equation of a tangent line to a function 2007-10-04
Princess pose la question :
If f ' (x) = 3x^2 +1, find the equation of the tangent line to f(x) = x^3 + x at x= -1.
Stephen La Rocque lui répond.
Hitting golf balls 2007-10-03
Jessi pose la question :
Ben is out at the practice range hitting golf balls. How much further will a golf ball with an initial speed of 75.0 m/s go when projected at 45.0 degree than when projected at 30.0 degree?
Stephen La Rocque lui répond.
Will the stone catch up the parachute? 2007-10-03
anoi90 pose la question :
a small parachute dropped from a 30.0 m high cliff falls with a constant velocity of 1.20 m/s. 20.0 s after the parachute is dropped, a stone is dropped from a cliff. Will the stone catch up the parachute before it reaches the ground? (Include numerical proof!)
Stephen La Rocque lui répond.
Motion along a line 2007-10-02
Claudette pose la question :
If the position function of a particle is x(t) = sin^2(2t), find the distance that the particle travels from t = 0 to t = 2
Harley Weston lui répond.
A tangent line to a circle 2007-09-26
Randy pose la question :
Find the equation of the tangent line at coordinates (-1 , 4) on the circle x^2 + y^2 - 4x - 21 = 0

I would like to learn the fastest way to relate any coordinates of a circle to any possible point of tangency.

Stephen La Rocque lui répond.
Can you tell me how many gallons it holds? 2007-09-25
Jeff pose la question :
Hi my water tank is 10ft long and 45" around,can you tell me how many gallons it holds.thankyou jeff
Penny Nom lui répond.
Finding equations, intersection point of two lines at right angles 2007-09-22
Yaz pose la question :
Find the equation of the line joining A(-1,-9) to B(6,120). Another line passes through C(7,-5) and meets AB at rigth angle of D. Find the euation of CD and calculate the co-ordinates of D.
Stephen La Rocque lui répond.
Points that are 15 units from the origin 2007-09-20
Paula pose la question :
Find the coordinates of any point(s) 15 units away from the origin with an x-coordinate of 9.

I was given the answer: (9,12) and (9,-12), but I do not understand how these numbers were calculated. Thank you for your help!

Stephen La Rocque lui répond.
A rectangle inscribed in a circle 2007-09-11
Sobeida pose la question :
A rectangle that is x feet wide is inscribed in a circle of radius 8 feet. What is the area of the rectangle as a function of x. Thanks!
Stephen la Rocque lui répond.
Water in a conical tank 2007-09-10
Greg pose la question :
Joe is conducting an experiment to study the rate of flow of water from a conical tank. The dimensions of the conical tank are:
Radius at the initial water level = 13.7 cm
Radius at the reference point = 12.8 cm
Initially the tank is full of water. There is a circular orifice at the bottom of the conical tank with a diameter of 0.635 cm. The water drains from the conical tank into an empty cylindrical tank lying on its side with a radius of 0.500 ft and a length L (ft).

Joe observed the water discharged with an average velocity of 1.50 m/s as the water level lowered from the initial height of 14.0 cm to 5.00 cm in the conical tank. Answer the following: 1. If the initial height of water in the conical tank is 14.0 cm (measured from the reference point, see Fig. 1), how long in seconds will it take for the water level to drain to a height of 5.00 cm?? NOTE: Height refers to the vertical height.

What formula would I use to find out how long in seconds it takes for the water level to drop?

Harley Weston lui répond.
Standard deviation 2007-09-05
Ethan pose la question :
Okay I have a question about standard deviation. Can you tell me a five number set of data that will have a standard deviation f zero and how you know that?
Stephen la Rocque lui répond.
The tangent to y = x^3 at x = 0 2007-09-04
Amit pose la question :
consider the equation = x^3. The equation of tangent to this curve (which is smmetrical in Ist and IVth quadrant) at (0,0) is y=0, which is x-axis. but graphically one can visulize that x-axis intersects the curve, so how can it be the tangent to the curve. Please help.
Harley Weston lui répond.
Standard deviation 2007-09-01
Pat pose la question :
I have looked over your math question and mines is not there. for a binomiial distribution with parmeter n and p, the mean is np and the standard deviation is np(1-p). I understand how to get the np but not understanding how to get the (1-p). For example np=(40)(0.48)(1-0.48)=3.160. How can I get the (1-0.48) answer please
Harley Weston lui répond.
A circle and a tangent 2007-08-27
Lindsay pose la question :
Hello. I'm trying to do a math problem and have searched the internet for equations but have come up empty handed. If you could help, that would be greatly appreciated! The problem is stated thus: A circle is tangent to the y-axis at y=3 and has one x-intercept at x=1.
a. Determine the other x-intercept
b. deduce the equation of the circle.

Penny Nom lui répond.
Two-column proof for a circle geometry problem 2007-08-24
Kendra pose la question :
i have to prove that tangents to a circle at the endpoints of a diatmeter are parallel by stating whats given, whats to prove and a plane, then write a two column proof i dont understand this
Stephen La Rocque lui répond.
Tangents to a circle 2007-08-18
Laura pose la question :
I have tangents from point A and B that intersect at C. A third tangent XY lies in between the two lines that I have already drawn. I measured the perimeter and then I drew another line that was tangent to the circle and was inside the two lines again and measured the perimeter again. The perimeters were the same but I don't know how to prove why this happened and write a theorem for it.
Chris Fisher lui répond.
Area and perimeter 2007-08-16
sheryl pose la question :
a 50*70 horse pen is 240 feet and 3500 square feet a 60*60 horse pen is 240 feet and 3600 square feet why is there a 100 square feet difference?
Penny Nom lui répond.
Two circles C1 and C2 meet at the points A and B 2007-08-15
Jerry pose la question :
Two circles C1 and C2 meet at the points A and B. The tangent to C1 at A meets C2 at P. Point Q inside C1 lies on the circumference of C2. When produced, BQ meets C1 at S and PA produced at T. Prove that AS is parallel to PQ.
Chris Fisher lui répond.
The area and perimeter of a rectangle 2007-08-15
Brooklyn pose la question :
Is there a way to find the perimeter of a rectangle if you have the area, or vice versa? If so, what is the equation?
Leeanne Boehm and Penny Nom lui répond.
Circle Geometry 2007-08-14
Robin pose la question :
In a triangle ABC, angle A=75 and B=60. A circle circumscribes the triangle. The tangents of the at points A and B meet in a point D outside the circle. Show that ABD is an isosceles triangle with a right angle at D. Diagram included.
Stephen La Rocque lui répond.
A round reservoir 2007-08-14
lee pose la question :
if you have a 46 acre round reservoir, how far around in feet would that be ??
Penny Nom lui répond.
Diagonals on a cylinder 2007-08-10
John pose la question :
I have a cylinder that is 37.5" width X 25.25" circumference. I need to create a repeating diagonal lined pattern on the cylinder so that when it prints it joins perfectly at the circumference repeat. The design must follow these specs. Black diagonal lines need to be 1.250" max width X 1.5" max spacing between the black lines. Please Help
Stephen La Rocque lui répond.
Find the dimensions of the rectangle that will contain the greatest area 2007-08-06
Julirose pose la question :
The perimeter of a rectangle is 38 meters. Find the dimensions of the rectangle that will contain the greatest area.
Penny Nom lui répond.
Three runners on a circular track 2007-08-04
Arul pose la question :
A, B and C run around a circular track starting from the same point simultaneously and in the same direction at speeds of 4 kmph, 6 kmph and 8 kmph respectively. If the length of the track is 400 meters, when will A, B and C meet at the starting point for the first time after they started the race?

4 In the above question, when will they meet for the first time after they started the race?

Penny Nom lui répond.
A statistics example 2007-08-02
Claudia pose la question :
A particular employee arrives to work some time between 8:00 am - 8:30 am. Based on past experience the Company has determined that the employee is equally likely to arrive at any time between 8:00 am - 8:30 am.

On average, what time does the employee arrive?

What is the standard deviation of the time at which the employee arrives?

Find the probability that the employee arrives exactly at 8:12 am?

Find the probability that the employee arrives between 8:20 am - 8:25 am?

Har lui répond.
At what speed does Chuck travel? 2007-07-27
Jessica pose la question :
Chuck and Dana agree to meet in Chicage for the weekend. Chuck travels 224 miles in the same time that Dana travels 204 miles. If Chuck's rate of travel is 5 mph more than Dana's, and they travel the same length of time, at what speed does Chuck travel?
Harley Weston lui répond.
A football stand 2007-07-19
jean pose la question :
a football stand 150 yd. long has 20 tiers of seats; each has a rise of 2 ft. and tread of 3 ft. it constructed of reinforced concrete with a cross section of 36*54. find the amount of material used in its construction.
Harley Weston lui répond.
Proving a quadrilateral is a rectangle 2007-07-14
Sonja pose la question :
I was having this discussion with another teacher and we need a third opinion. When you are trying to prove a quadrilateral is a rectangle which method should you use:
  1. Prove the shape is a parallelogram by doing slope 4 times by stating that parallel lines have equal slopes. Then proving a right angle by stating that perpendicular lines have negative reciprocal slopes.
  2. Doing the slope 4 times and stating that the shape is a rectangle because opposite sides are parallel because of equal slopes and it contains a right angle because of negative reciprocal slopes.
I guess the real question is do you have to first state that the shape is a parallelogram?

Stephen La Rocque lui répond.
Finding the radius of an inscribed circle 2007-07-05
Maria pose la question :
I need to find the radius of a circle which is inscribed inside an obtuse triangle ABC. I know all the angles and all the lengths of the triangle.
Stephen La Rocque and Chris Fisher lui répond.
Algebraic EquationsAx+By=C 2007-07-02
Juan pose la question :
The general "Standard" form of an equation is Ax+By=C. Re-Write this equation in slope-intercept (y=mx+b) form.
Harley Weston lui répond.
Simultaneous equations : the Elimination method 2007-06-21
Patricia pose la question :
I need to find the value of X and Y using the Elimination method.

5/x + 3/y=4
25/x-2/y=3

Stephen La Rocque lui répond.
How many gallons of water 2007-06-19
Marie pose la question :
A water treatment plant is built with three cylindrical tanks to contaim the water for a town. Each tank has a radius of 15 feet and a depth of 25 ft.

If there are about 7.5 gallons in a cubic foot of water, approximately how many gallons of water can be treated at the plant at any one time?

Stephen La Rocque lui répond.
A square and a rectangle 2007-06-19
Clarence pose la question :
What is the difference between rectangle and a square
Penny Nom lui répond.
Simultaneous inequalities 2007-06-18
Freddy pose la question :
Watson Electric has production facilities in Valley Mills, Marlin,and Hillsboro. Each one produces radios,stereos,and TV sets. There production capacities are

Valley Mills: 10 radios, 12 stereos, and 6 TV sets per hour Marlin: 7 radios, 10 stereos, and 8 TV sets per hour Hillsboro: 5 Radios, 4 Stereos, amid 13 TV sets per hour

QUESTION

How many hours should each plant be scheduled to fill an order of 1095 radios, 1230 stereos, and 1490 TV sets?

Stephen La Rocque lui répond.
Circumscribing a golden cuboid with a sphere: surface areas 2007-06-14
Ainslie pose la question :
A golden cuboid is defined as a rectangular prism whose length, width and height are in the ratio of phi : 1 : 1/phi.
Prove that the ratio of the Surface Areas of the golden cuboid to that of the sphere that circumscribes it is Phi : Pi.

Stephen La Rocque lui répond.
Angles of depression 2007-06-13
Phonda pose la question :
The pilot of a small private plane can look forward and see the control tower for a small airstrip. Beyond that is a large factory that is 3 milies from the airstrip. The angles of depression are 12.5 degrees and 4.8 degrees respectively. Find the airplane's altitude, to the nearest ten feet.
Stephen La Rocque lui répond.
Standard Deviation 2007-06-13
Adrian pose la question :
If you are told that the mean salary of a certain group of workers is $30,000 with a standard deviation of $4000, what proportion of workers earn over $38,000? What proportion of workers earn less than $18,000? Assume the distribution of wages is normal.
Stephen La Rocque lui répond.
Throwing a ball from the top of a building 2007-06-12
Gilligan pose la question :
s = distance (in feet)
Building height = 96 feet
t = seconds
Use s = 96 + 80t - 16t^2 to answer the question given below.

QUESTION:
After how many second t will the ball pass the top of the building on its way down?

Penny Nom lui répond.
Two tangent lines to y=x^3 2007-06-07
stephanie pose la question :
find the equations of two tangent lines to the y=x^3 function through the point (2,8)
Penny Nom lui répond.
Water tank volume 2007-05-29
Cecelia pose la question :
I HAVE A SEMI CIRCULAR TANK AGAINST A WALL MEASURING 6'10" ACROSS THE WIDEST PART AND 3' FROM THE WALL TO THE FRONT OF THE TANK. THE DEPTH IS 14". PLEASE HELP ME TO CALCULATE THE VOLUME OF WATER IN THE TANK.
Stephen La Rocque lui répond.
System of equations 2007-05-24
Chris pose la question :
Find all real solutions (x,y,z,w) of the system of equations:
2y= x + x/17, 2z= y + y/17, 2w = z + z/17, 2x= w + w/17

Penny Nom lui répond.
Normal distribution 2007-05-24
Paula pose la question :
Consider a data set that is normally distributed. The mean of the data set is equal to 10,000.
a.) Suppose that, for this data set, 10,625 has a "z-value" = 2.5. Solve for the standard deviation of the data set.
b.) Solve for the "z-value" of 9,900.

Penny Nom lui répond.
Set up two simultaneous equations 2007-05-21
Admire pose la question :
The cost of producing windscreen wipers blades at a factory ais partly fixed (due to operating overheads) and partly dependent on the number of blades produced. It costs $300 to produce 1000, and $600 to produce 5000 blades. How much would it cost to produce 24000 blades?
Penny Nom lui répond.
Finding the hypotenuse without Pythagorus 2007-05-11
Shelbie pose la question :
How do i find the hypotenuse of a right traingle not using the pythagorean thereom if i have the measurements of the legs?
Stephen La Rocque lui répond.
Are proofs important in geometry? 2007-05-07
BJ pose la question :
Are proofs very important to know how to do?
My daughter has been in Geometry & the teacher skipped proofs.

Penny Nom lui répond.
The dimensions of a rectangle 2007-05-07
Stephanie pose la question :
The perimeter of a rectangle is 54yds , and the area of the rectangle is 180yds^2 . Find the dimensions of the rectangle.
Penny Nom lui répond.
A tugboat's speed 2007-04-30
Amanda pose la question :
a tugboat must travel 24 miles against a 4 mile per hour current on the Potomac River and return. At what constant speed must the tugboat travel to make the trip in 12 hours. Round answer to the nearest tenth mph.
Stephen La Rocque lui répond.
I have N data points in m-dimensional space 2007-04-29
Sid pose la question :
Hi, Given below is the problem that I am facing: I have N data points in m-dimensional space. I know the mean euclidean distance of the points from one given point (say the origin). Now I wish to find the mean Euclidean distance of the N points from another given point. How can i do this without knowing the values of the N points and only knowing the 2 origin points and the mean distance from one of the origin points ?
Penny Nom lui répond.
Incremental standard deviation 2007-04-28
Murtaza pose la question :
Hi In relation my question asked earlier, i would first like to thank you for the prompt reply. But it has not answered my query yet. Let me frame the problem again. I have a mean value for N data items. (note that i know N but i donot know the distinct N data item values) Now the (N+1)th data item comes in and i calculate the new mean. (incremental method for that is simple). How do i calculate the new standard deviation. The formula you gave me requires me to read the data items once and at the end of the pass i will have have the standard deviation. But i need the STDDEV values at intermediate stages as well. Is it possible ? Murtaza
Penny Nom lui répond.
What is the speed of the boat? 2007-04-22
Sonja pose la question :
A boat on a river travels downstream between two points, 20 miles apart, in one hour. The return trip against the current takes 2 1/2 hours. What is the speed of the boat? The answer in the book says 14 mi/hr, but I don't understand how to figure it out. It must be very simple, but I'm stuck. Thank you so much for helping me out. This is a FANTASTIC website! -Sonja
Penny Nom lui répond.
Two tangents to a circle 2007-04-17
Doug pose la question :
Two distinct, nonparallel lines are tangen to a circle. The measurement of the angle between the two lines is 54 degrees (angle QVP). Suppose the diameter of the circle is 2 cm. What is the distance VP? Suppose the distance VP is 3.93 cm. What is the diameter of the circle? Find a formula for d, the diameter of the circle, in terms of VP. Find a formula for VP in terms of d, the diameter of the circle.
Stephen La Rocque lui répond.
A gardener has 140 ft of fencing to fence 2007-04-16
Johann pose la question :
A gardener has 140 ft of fencing to fence in a rectangular shaped vegetable garden. To plant all his vegetables, the gardener needs more than 825 sq ft of space. What are the possibles values for the length of the rectangle that would meet the space requirements? You may assume that the variable x represents the length of the rectangle.
Stephen La Rocque lui répond.
Simultaneous equations 2007-04-16
kyrie pose la question :
simultaneous equation 4x + 3y = 21 2x * y = 8
Penny Nom lui répond.
How far apart are the cars? 2007-04-07
ian pose la question :
2 cars set off in opposite directions and travel for 6 miles, they both take a left turn, and travel for a further 8 miles........... how far apart are the cars???

a) 10 miles
b) 22 miles
c) 20 miles
d) 18 miles

Penny Nom lui répond.
A delivery driver travels from Belfast to an address in Dublin 2007-04-04
Gerry pose la question :
A delivery driver travels from Belfast to an address in Dublin.The total distance fro the round trip was x%.The time required for the forward trip was xx hours.Due to heavy traffic during the return trip an extra xx was required How much slower was the delivery drivers speed on the return trip?.

I was wondering what equation would you use to solve this question.

Penny Nom lui répond.
Tina swims 4 miles upstream at 1 mph 2007-03-31
Michael pose la question :
If Tina swims 4 miles upstream at 1 mph and back downstream to the same point to the same point at 4 mph, what is her average speed?
Penny Nom lui répond.
Acceptance sampling 2007-03-29
Katrina pose la question :
The Medassist Pharmaceutical Company recieves large shipments of asprin tablets and uses this acceptance sampling plan: Randomly select and test 24 tablets, then accept the whole batch if there is only one or none that doesnt meet the required specifications. If a particular shipment of thousands of asprin tablets actually has a 4% rate of defects, what is the probability that this whole shipment will be accepted?
Penny Nom lui répond.
The angles in a right triangle 2007-03-28
Golaan pose la question :
I need the to understand the formula for finding either of the acute angles of a right triangle given it's hieght length and base length. I want to find the degrees of either accute angle. So for this example I have a right triangle with a height of 410 meters and a base length of 1,700 meters. I don't understand cosine, sine, and tangent or the other ones at all. So if the solution includes those (which I believe it does) could b very verbose yet in a very elementary way?

The purpose of ths is that I have to define the general incline angles (or grade) of various areas of terrain. I know the distance by map and also the the altitude at either endpoint.

Penny Nom lui répond.
An inheritance problem 2007-03-23
Carl pose la question :
A father of 3 boys, who owns 17 horses dies. He leaves his first son 1/2 of the horses. The sons hate each other. The father leaves the second son 1/3 of the horses. They are ready to kill each other. He leaves his youngest son 1/6 of the horses. Without cutting the horses into pieces how do they split the horses? I heard this puzzle when I was 12 years old. 1968 The preacher rides up on his horse and said "If I give you my horse will you quit fighting ? They agree to stop fighting?" Why?
Penny Nom lui répond.
A one pass calculation of standard deviation 2007-03-19
Murtaza pose la question :
Hi I searched the listings but couldn't find what i am looking for. I have a dataset and i am allowed only 1 pass through it. At the end of this pass i must have the mean and standard deviation. Calculating the mean is easy as also demonstrated in your listings. I think the same can be done for standard deviation as well. But the doubt that i have is this :- Will the calculated standard deviation be sequence dependent ? i.e. if i change the order in which the data items enter the system, will the std deviation also change ?? Thanks in advance Murtaza
Penny Nom lui répond.
Triple angle tangent formula 2007-03-15
sam pose la question :
Hi I am trying to derive a triple angle formulae for tan. I know i need to use compound and double angle formulae but am finding it difficult to "clean" up my fraction to get the triple angle formulae can you show me a worked derivation?! thanks
Penny Nom lui répond.
Two busses 2007-03-15
Devon pose la question :
A bus leaves a station at 1 p.m., traveling west at an average rate of 44 mi/h. One hour later a second bus leaves the same station, traveling east at a rate of 48 mi/h. At what time will the two buses be 274 mi apart?
Steve La Rocque and Penny Nom lui répond.
The dimensions of a rectangle with least perimeter for given area 2007-03-14
Karlianna pose la question :
find dimensions of a rectangle with least perimeter for given area
A) 30cm2
b) 50cm2

Penny Nom lui répond.
Angle of elevation 2007-03-13
Joslyn pose la question :
A ship at sea sights a 12m high lighthouse on a cliff which is 80m above sea level. If the angle of elevation to the top of the lighthouse is 27 degrees, calculate the distance from the ship to the shore.
Haley Ess lui répond.
Simultaneous equations with fractions 2007-02-28
Alyca pose la question :
Hello Math Central, I am a grade 10 student taking Academic math. Our unit right now is method of substitution and elimination. I'm stuck on this one question that I've been doing forever. Please help =)

*For this equation I have to do method of elimination, but it's so much harder with fractions...could some one please explain to me how to do it step by step?*
x y 2
-- - -- = - --
3 6 3

x y 1
-- - -- = 1---
12 4 2

Steve La Rocque and Ashley Mang lui répond.
How long does she have to get out of the way? 2007-02-23
Sharon pose la question :
How do I solve this? The height h (in feet) of an object that is dropped from the height of s feet is given by the formula h = s - 16t^2 , where t is the time the object has been falling. A 6 foot tall woman on a sidewalk looks directly overhead and sees a window washer drop a bottle from the 6 story. How long does she have to get out of the way? Round to the nearest tenth. (A story is 12 feet.)
Penny Nom lui répond.
Finding the equation of the circle 2007-02-20
ning pose la question :
Given the radius of a circle square root of 10 tangent to the line 3x+y+19 = 0 and passing through (0,-3), how can i solve the equation of circle? thank you...
Chris Fisher, Steve La Rocque and Penny Nom lui répond.
A common tangent line 2007-02-20
chris pose la question :
I have this problem I have been working on for days and cannot figure it out. it states: Find the two points on the curve y=x^4 - 2x^2 - x that have a common tangent line.

I know you use the first derivative to find the tangent line so if it is a common tangent line should you find two of the exact same tangent line equations at two coordinate points?

Chris Fisher lui répond.
How far from the port is the point where the ship turned? 2007-02-19
Chris pose la question :
I was confused on this problem. If a ship leaves port and travel due east. At a certain point it turns 65 degrees south of east and travels b=322 nautical miles to a point 461 nautical miles on a direct line from port. How far from the port is the point where the ship turned?
Stephen La Rocque lui répond.
Increasing speed and decreasing time 2007-02-18
Nigel pose la question :
I am completely lost...can you help with this: The time, t, to travel a distance, d, at a constant speed, v, can be obtained from the formula: d = vt. If the speed is increased by x, find an expression to represent the decrease in time to travel the same distance.
Stephen La Rocque lui répond.
Square centimeters 2007-02-12
Ivan pose la question :
how many square centimeters are in a rectangle that is 210 centimeters long by 39 centimeters wide.? thank you
Karen McIver and Melanie Tyrer lui répond.
Simultaneous equations with envelopes 2007-02-08
Mick pose la question :
There were 17 envelopes bought, some were brown, some were white. The brown envelopes cost one cent more per envelope than the white ones. The total cost was 80 cents. How much of each type of envelope was bought? --Many thanks!
Stephen La Rocque lui répond.
Romeo is throwing pebbles 2007-02-08
Jessie pose la question :
Romeo is chucking pebbles gently up to Juliet's window, and he wants the pebbles to hit the window with only a horizontal component of velocity. He is standing at the edge of a rose garden 4.5m below her window and 5.0m from the base of the wall. How fast are the pebbles going when they hit her window?
Stephen La Rocque lui répond.
Area of a rectangle 2007-02-07
kyle pose la question :
paul has enough material to make a fence 22 feet long. he will use this material to fence of a rectangular section of his yard. the rectangles sides must all be whole numbers. i am having a hard time finding the greatest and the least area that he can enclose his fece
Haley Ess lui répond.
A rectangle inscribed in a circle 2007-02-04
Benneth pose la question :
Consider a rectangle with radius R inscribed in a circle. What are the possible areas of the rectangle?
Steve La Rocque and Walter Whiteley lui répond.
Rectangles and squares 2007-01-31
Shelby pose la question :
I am doing homework and I need to know why squares are rectangles but not all rectangles are squares?
Penny Nom lui répond.
The substitution method 2007-01-31
Victoria pose la question :
how do i solve this problem using the substitution method?
2x-5= -14
-7x+14y= -5

Stephen La Rocque lui répond.
The elimination method 2007-01-31
Addrianna pose la question :
x-2y=2
3x-5y=7

Stephen La Rocque lui répond.
A thin wire 20 centimeters long is formed into a rectangle 2007-01-29
Trisha pose la question :
a thin wire 20 centimeters long is formed into a rectangle. if the width of this rectangle is 4 centimeters, what is the length?
Penny Nom lui répond.
A boat travels 60 miles downstream in the same time it takes to go 36 miles upstream 2007-01-27
Liz pose la question :
A boat travels 60 miles downstream in the same time it takes to go 36 miles upstream. The speed of the boat in still water is 15 mi/h greater than the speed of the current. Find the speed of the current.
Stephen La Rocque lui répond.
Freefalling objects 2007-01-25
Patricia pose la question :
How long will it take a stone dropped from atop a 1000-meter tall building to reach the ground?
Stephen La Rocque lui répond.
A college student jogs from his home to the beach 2007-01-23
Garmani pose la question :
A college student jogs from his home to the beach at 8 miles per hour. He visits with his friends on the beach for 4 hours, and then his friends drive him home at the rate of 40 miles per hour. If the student returns home after 6 hour, what is the distance from his home to the beach?
Penny Nom lui répond.
What is the speed of each boat per hour? 2007-01-22
Garmani pose la question :
Two tuna boats leave the same port traveling in opposite directions along the west coast of the United States. One boat travels 5 miles per hour faster than the other. At the end of one day's travel they are 1,080 miles apart. What is the speed of each boat per hour?
Penny Nom lui répond.
A formula for figuring a tanks volume at various levels 2007-01-20
Dave pose la question :
I know there has to be a general formula to figure out a tanks volume where as you know the total volume but you need to know what it will hold at various levels measured in 1/8th inches in depth and that you may be able to plug this formula into a program like say excel and thus create a chart unique to that tank. But for the lack of me I can not figure it out.
Stephen La Rocque lui répond.
Depth and volume in a cylindrical tank 2007-01-20
Andy pose la question :
I need to fill a 10 foot diameter by 35 foot long cylinder 85% full. Is there a way to calculate at what depth equals 85%? ie, if I put a stick in the tank would it be at 8.5 feet?
Stephen La Rocque lui répond.
At what speeds were they travelling? 2007-01-16
Maria pose la question :
Kim and Julie are joining Nicole at her parents cottage for the weekend. The cottage is 150km away from their neighbourhood. Kim can leave directly after school but Julie will be leaving after band practice, an hour and a quarter later. Kim took her time and drove slowly, averaging 20km/h slower than Julie. They both arrived at the same time.
At what speeds were they travelling?

Stephen La Rocque lui répond.
Standard deviation 2007-01-15
Kayleigh pose la question :
After i have added up all the squared deviations what do i do???, what is meant by "divide by one less than the sample size"
Stephen La Rocque lui répond.
What is his rate of walking for the entire trip? 2007-01-12
Garmani pose la question :
A man walks 500 feet at 4 miles per hour and returns to the starting point at 3 miles per hour. What is his rate of walking for the entire trip?
Stephen La Rocque lui répond.
Throwing a stone downwards 2007-01-12
Momo pose la question :
a stone is thrown vertically downward with an initial speed of 14m/s from a height of 65 m above the ground. A) how far does the stone travel in the first 2.0 s? B) what is the stone velocity just before it hits the ground?
Stephen La Rocque lui répond.
Find the area of the rectangle 2007-01-09
Mike pose la question :
The perimeter of a rectangle is 72 in. The base is 3 times the height. find the area of the rectangle?
Penny Nom lui répond.
What is the speed of the current? 2007-01-07
Bob pose la question :
A motorboat can maintain a constant speed of 16 miles per hour relative to the water. The boat makes a trip upstream to a certain point in 20 minutes; the return trip takes 15 minutes. What is the speed of the current?
Haley Ess lui répond.
Are all rectangles trapezoids? 2007-01-05
Sarah pose la question :
Are all rectangles trapezoids?
Chris Fisher lui répond.
A quuadratic equation 2006-12-22
Harold pose la question :
L=3w-4
A=96Square
I used the quadratic equation to solve and my answer is still wrong

I convert the square of 1168 to decimal.

here is where i start
(3w-4) x w=96

could you give me an example

Stephen La Rocque lui répond.
Cary was going to meet Jane at the airport, ... 2006-12-11
Carmen pose la question :
cary was going to meet jane at the airport, if he traveled 60mph, he would arrive one hour early, and he traveled 30 mph, he would arrive one hour late. how far was the airport? recall: distance=speed(time)
Stephen La Rocque lui répond.
Rate of a boat and a river 2006-12-09
Dale pose la question :
If a boat goes downstream 72 miles in 3 hours and upstream 60 miles in 6 hour, the rate of the river and the rate of the boat in still water respectively are ____?
Stephen La Rocque lui répond.
The Metra and the Amtrack 2006-12-03
Amy pose la question :
A Metra commuter train leaves Union Station in Chicago at 12 noon. Two hours later, an Amtrak train leaves on the same track, traveling at an average speed that is 50 miles per hour faster than the Metra train. At 3PM the Amtrak train is 10 miles behind the commuter train. How fast is each going?
Stephen La Rocque and Penny Nom lui répond.
A trip on the Grand River 2006-11-30
Kristy pose la question :
Romo decided to make a 28km trip up and 28km trip down the Grand River. the speed of the current is 3km. one way Romo travelled with the current and the other way against the current. During his trip, Romo stopped for half an hour for lunch. if Romo's total trip lasted 6hours, how fast did he travel?
Stephen La Rocque lui répond.
Dimensions of a rectangle 2006-11-22
Terri pose la question :
How can you find the dimensions of a rectangle that has a perimeter of 18 feet?
Stephen La Rocque lui répond.
Circle geometry 2006-11-19
Namrata pose la question :
AB is a diameter and AC IS A CHORD OF A CIRCLE SUCH THAT angle=30. the tangent at C intersect AB produced in a pointD. Prove that BC=BD.
Stephen La Rocque lui répond.
Two trains left the station at the same time and traveled in opposite directions. 2006-11-18
Tori pose la question :
Two trains left the station at the same time and traveled in opposite directions. The E train averaged 130 km/h. The A train's speed was 110 km/h. In how many hours were they 480 km apart?
Stephen La Rocque lui répond.
Find the distance function s(t) given the acceleration function a(t) 2006-11-16
David pose la question :
Find the distance function s(t) of the acceleration function: a(t)= sin(0.1t)/ cos^3(0.1t)
Penny Nom lui répond.
Tangent lines 2006-11-09
Melissa pose la question :
let f be a function with f(1)=4 such that for all points (x,y) on the graph of f the slope is given by (3x^(2)+1)/(2y)

a.)Find the slope of the graph of f at the point where x=1.
b.)Write an equation for the line tangent to the graph of f at x=1 and use it to approximate f(1.2)
c.) Find whether f is concave up or concave down when x=1. Is your answer in part b an overestimate or an underestimate?

Stephen La Rocque lui répond.
Simultaneous equations 2006-11-06
An other pose la question :
e^2y-x+2=0
ln(x+3)-2y-1=0

Penny Nom lui répond.
Going from one town to another 2006-11-04
Austin pose la question :
Going from one town to another,a man drives his car at 35 miles an hour and returning he drives at 25 miles an hour. the round trip takes 6 hours. Find the distance between the towns.
Stephen La Rocque lui répond.
The dimensions of a rectangle 2006-11-02
Ben pose la question :
A rectangle's length is 8 cm. greater than its width. Its perimeter is 128 cm. Find its dimensions.
Penny Nom lui répond.
Paddeling on the Alleman River 2006-10-31
Anita pose la question :
Len is planning a three-hour trip down the Alleman River and back to his starting point. He knows that he can paddle in still water at 3 mph and that the rate of the current is 2 mph. How much time can he spend going downstream? How far downstream can he travel?
Penny Nom lui répond.
The distance from a point to a line in 3 space 2006-10-29
Marie pose la question :
find the distance from the point (1, -2, -3) to the line x = y = z-2
Penny Nom lui répond.
How do you find the length and width of a rectangle if you know ... 2006-10-15
Anne pose la question :
How do you find the length and width of a rectangle if you know the perimeter of the rectangle is 48 m and the area is 144 m squared?
Stephen La Rocque and Penny Nom lui répond.
Standard deviation 2006-10-04
Jennifer pose la question :
I was wondering how to figure out a standard deviation if you only have the mean of the data and no other information?
Stephen La Rocque lui répond.
A 5x2 rectangle 2006-10-03
Stanley pose la question :
Cut a 5x2 rectangle into 4 pieces, and then put them back into as a square.
Claude Tardif and Penny Nom lui répond.
How long will it be before the two snails meet? 2006-09-21
Brett pose la question :
Two snails are 8.5 feet apart. They start to crawl toward each other at the same time. One of them travels at the speed of 6 in. per minute, while the other zips along at 11 inches per minute. How long will it be before the two snails meet?
Penny Nom lui répond.
A rectangular tank 2006-09-19
Milton pose la question :
What size rectangular tank will I need to hold 841.5 gallons of water. The water level is 3'-0" from the bottom of tank.
Penny Nom lui répond.
Convert a standard form to a slope intercept form 2006-09-14
Maiko pose la question :
I need to know step by step procedures to convert a standard form to a slope intercept form?
Penny Nom lui répond.
How high (in feet) is the mountain? 2006-08-29
Briana pose la question :
A survey team is trying to estimate the height of a mountain above a level plain. From one point on the plain, they observe that the angle of elevation to the top of the mountain is 29 degrees. From a point 2000 feet closer to the mountain along the plain, they find that the angle of elevation is 31 degrees. How high (in feet) is the mountain?
Stephen La Rocque lui répond.
The capacity of our hexagon fish tank 2006-07-26
Doug and Andrea pose la question :
My name is Andrea and my son, Doug, and I were wondering what the capacity of our hexagon fish tank was but it’s been so long since I’ve been to school that I’ve forgotten the formula to do so. Would you please help us? The dimensions are: 27 ¾ W x 24L x 29H or one side (glass panel) is 14W x 29H.
Penny Nom lui répond.
The dimensions of a rectangle 2006-07-09
Lori pose la question :
The length of a rectangle is 1 cm more than 3 times its width. If the area of the rectangle is 61 cm2, find the dimensions of the rectangle to the nearest thousandth.
Penny Nom lui répond.
Flying with and against the wind 2006-07-06
Tim pose la question :
When a plane flies with the wind, it travels 800 miles in 4 hours. Against the wind it takes 5 hours to cover the same distance. Find the rate of the plane in still air and the rate of the wind.
Stephen La Rocque lui répond.
A tangent to a circle 2006-07-05
Izumi pose la question :

I have problems finding the point of tangency between the circle C

x2 + y2 + 4x - 6y - 12 = 0

and the tangential line that passes through the point P (6, -1).


Stephen La Rocque lui répond.
A boat travels 60 miles upstream ... 2006-05-28
Teenarick pose la question :
A boat travels 60 miles upstream against the current in 3 hours. It takes 2 hours for the return trip. Find the speed of the boat in still water.
Penny Nom lui répond.
Simultaneous Equations 2006-05-24
Angie pose la question :

Question: solve the equations
2x-3y-z=0
3x-2y+z=-5
x+3y-2z=14

for x,y,z


Stephen La Rocque lui répond.
The interior angles of a right triangle 2006-05-20
Greg pose la question :
I am wondering if there is a way to figure out the interior angles of a right triangle if we know ONLY the side lengths, and the trick is, we CANNOT use arctangent!
Leeanne Boehm and Penny Nom lui répond.
The distance to the moon from earth 2006-05-19
Maira pose la question :
Using trigonometric functions first, show how to find the distance to the moon from earth and then find the radius of the moon.
Stephen La Rocque lui répond.
Absolute Value vs. Standard Deviation ? 2006-04-24
Sonia pose la question :
Why we don't just take the average of the absolute value of difference scores (use the mean deviation) to describe variability instead of calculating the standard deviation?
Claude Tardif lui répond.
Geometry proof 2006-04-23
Jade pose la question :
From a point P outside a circle with centre O, tangents are drawn to meet the circle at A and B. a) Prove that PO is the right bisector of the chord AB. b) Prove that
Stephen La Rocque lui répond.
Distance to the horizon 2006-04-20
Raymond pose la question :
If I stand on the edge of the sea on a beach and look into the horizon, is there a way or formula for calculating the distance from myself to the horizon?
Stephen La Rocque lui répond.
Two circles 2006-04-07
Louisa pose la question :
One circle of radius 7cm is touching another circle of radius 4cm. These circles are on a line and the problem is to find the length AB where A is the point marking the bottom of the radius of one circle and B is the point marking the bottom of the radius of the other circle.
Stephen La Rocque lui répond.
2x+5y=3 And -x+3y=-7 2006-04-03
Lloyd pose la question :
simplify 2x+5y=3 And -x+3y=-7
Penny Nom lui répond.
Wes and Tony live 360 km apart. 2006-04-01
Thiru pose la question :
Wes and Tony live 360 km apart. If Wes travels at 80 km/h towards Tony. And Tony travels at 100 km/h towards Wes, how long will it take before they meet.
Penny Nom lui répond.
How far from Earth is Neptune? 2006-03-21
Scott pose la question :
A laser beam travelling at the speed of light bounces off the planet Neptune and returns to Earth in 29 960.72 s. The speed of light is 299 792.5 km/s. How far from Earth is Neptune?
Penny lui répond.
If a circle is elongated into an oval .. 2006-03-16
Bruce pose la question :
If a circle is elongated into an oval, with constant circumference, does the area remain constant?
Walter Whiteley lui répond.
A 3-dimensional star 2006-03-15
Rachel pose la question :
I am trying to figure out the name of a figure that consists of 8 (I think) square pyramids. There is a net drawing of this figure somewhere and I can't find it because I don't know the name. When all 8 pyramids are connected, they form a '3-dimensional star'. We did this project when I was 14 years old and I am now a 27 year old teacher and I would love to do this project with my kids.
chris Fisher lui répond.
Rectangles with the same perimeter 2006-03-14
Kristine pose la question :
If two rectangles have the same perimeter, will they also have the same area? Why
Penny Nom lui répond.
2x+3y=0 and 3x-y=0 2006-03-14
Lisa pose la question :
my name is lisa I am doing math for work and i have a math problem to solve and i need help with it here is the question 2x+3y=0 and 3x-y=0 this is one question can you help me please
Penny Nom lui répond.
The number of gallons in a tank 2006-03-09
Doug pose la question :
We have a round tank that is 216 inches long 64 inches wide across ; how do we find the number of gallons it could hold ?
Stephen La Rocque lui répond.
The volume & surface area of a rectangular pyramid. 2006-02-27
Cheryl pose la question :
My daughter is working on a math project & we are having a hard time finding the volume & surface area of a rectangular pyramid. Can you help us with this?
Penny Nom lui répond.
Luke and Slim have only one horse. 2006-02-26
Emily pose la question :
Luke and Slim have only one horse. Luke rides for the agreed on distance and then ties up the horse for Slim, who has been walking. Meanwhile, Luke walks on ahead. They alternate walking and riding. If they walk 4 miles per hour, and ride 12 miles per hour, what part of the time is the horse resting?
Penny Nom lui répond.
Traveling from Asheville to Indianapolis 2006-02-21
Grace pose la question :
Carol was traveling from Asheville, North Carolina, to Indianapolis, Indiana, by bus. At the halfway point of her trip, in terms of distance, she fell asleep. When she awoke, her distance to Indianapolis was half the distance that she had traveled while she slept. For what fraction of her trip did Carol sleep?
Penny Nom and Stephen La Rocque lui répond.
Related rates and an oil spill 2006-02-12
Brandon pose la question :

An Oil Tanker Spills 100,000 cubic meters of oil, which forms a slick that spreads on the water surface in a shape best modeled by a circular disc is increasing at a rate of 3m/min (it doesn't state what is increasing at 3m/min, so I'm assuming Radius until I can ask my teacher.) At t=T, the area of the "circular" slick reaches 100pi Sq. meters.

A) how fast is the area of the slick increasing at t=T
B)How fast is the thickness of the slick decreasing at t=T
C)Find the rate of change of the area of the slick with respect to the thickness at t=T.


Penny Nom lui répond.
Degree 2006-02-09
Jessica pose la question :
I am a 9th grade home school student and have started doing degrees of terms in my math book. The following is some examples they give:

25a to the 4th power is a 4th degree term

67c to the 9th power is a 9th degree term

x is really x to the 1st power so it is a 1st degree term

10 is really 10x to the 0 power so it is a 0 degree term

They go on to say that every constant is a zero degree term.

My question is why isn't a constant, like 10, simply to the 1st power (making is a 1st degree term) like x.

Claude Tardif lui répond.
A locus problem 2006-02-08
Jason pose la question :
If the distance from p(1,5) is 3/4 that of the distance of a(4,-3)? find the equation of a locus.
Penny Nom lui répond.
One boundary of a pond is parabolic in shape. 2006-01-20
Glenn pose la question :
One boundary of a pond is parabolic in shape. The boundary passes through the points A(-20,45), B(40,40) and E(30,35). The equation of the parabola is of the form y=ax2+bx+c. Find the equation of the parabola and the coordinates of the vertex of the parabola. Any assistance you could provide would be greatly appreciated.
Penny Nom lui répond.
A sequence of circles and tangents 2006-01-16
Paul pose la question :
Consider a circle whose center is (2,2) and whose radius is 1, and the straight line that goes through the origin and that is tangent to this circle so that the intersection between them is as shown in the attached picture. With this new point we make a new circle whose radius is half of the first one, and we calculate the corresponding intersection point with the same suppositions as in the first case. We repeat the process to the infinite. Find the distance between the center of the circle in the infinite and the origin (point (0,0)).
Chris Fisher lui répond.
What initial velocity is required to double the maximum height 2006-01-14
A photographer pose la question :
A body is thrown into the air with an initial velocity V ft./sec. What initial velocity is required to double the maximum height previously obtained?
Penny Nom lui répond.
60.5 ft at 90 mi/hr takes how long? 2006-01-13
Bree pose la question :
A ball travels over 60.5 ft at 90 mi/hr. How fast does the ball travel?
Penny Nom lui répond.
A rectangle has a length that is 7cm more than twice the width 2005-12-21
Stephanie pose la question :
A rectangle has a length that is 7cm more than twice the width. The area of the rectangle is 60cm squared. Find the dimensions of the rectangle.
Penny Nom lui répond.
Simultaneous Equations 2005-12-21
Matt pose la question :
I have these two equations,
336 = 60a + 10b
and
432 = 84a + 6b
Am I right in saying both a and b are 4.8?

Penny Nom lui répond.
Four tangent circles 2005-12-06
Ananth pose la question :

I have one bigger circle A with radius 15.

Inside this bigger circle i have another circle B with radius 3 which touch this bigger circle. Have another circle C with radius 4 which touches A and B. I would like to draw a biggest circle which touches A,B and C.


Chris Fisher lui répond.
A long distance call 2005-12-05
A student pose la question :
The Small World long distance phone company charges 55cents for the first minute of a long distance call and 23cents for each additional minute.

1. How much would a 10- minute long-distance call cost?

2. If a call costs $4.55. how long did the call last?

3. Write an equation for the total cost, C, of an m-minute long-distance call.

Penny Nom lui répond.
A standard normal probability 2005-11-19
Pat pose la question :
Find the probability of Z when it lies between -1.10 and -0.36
Penny Nom lui répond.
A variable rectangle 2005-11-08
Mussawar pose la question :
find the lengths of the sides of a variable rectangle having area 36 cm2 when its perimeter is minimum i do not want solution of this question. i would like to know what is mean by variable rectangle.and what is difference between rectangle and variable rectangle.also what is mean by when its perimeter is minimum.
Penny Nom lui répond.
Equidistant from the points (2,-1,1) and (0,1,3) 2005-11-06
Roy pose la question :

Find the point on the y-axis that is equidistant from the points (2,-1,1) and (0,1,3).

Find the point not on the y-axis that is equidistant from the points (2,-1,1) and (0,1,3).


Penny Nom and Walter Whiteley lui répond.
A tangent to a parabola 2005-11-02
A student pose la question :
Find the point on the curve y=x2 where the tangent to the curve is parallel to the secant line connecting (-1,1) and (2,4)
Penny Nom lui répond.
Simultaneous equations 2005-10-13
Daniel pose la question :
5x + 3y = 22 4x - 7y = -20
Penny Nom lui répond.
Means of sample means 2005-10-12
Fareeha pose la question :
A population consists of six numbers 1,2,3,4,5,6
a) How many different samples of two numbers can be selected with replacement? and list them.
b) Calculate the mean and standard deviation of the population
b2) Calculate the mean and standard deviation of the mean of the samples.
c) Find the standard error of your estimated mean in question b2 and compare with the estimated standard deviation in b2.

Penny Nom lui répond.
Coefficients, constants and like terms 2005-10-05
Elizabeth pose la question :
In the equation -8y+6ab+7-3ab what are the coefficients; the like terms and constants?
Penny lui répond.
City A is 30 miles directly north of City C 2005-10-04
A student pose la question :
City A is 30 miles directly north of City C, and City B is 40 miles directly east of City C. Cities A and B are connected by a straight road. Find the length of the shortest path from City C to the road that connects A and B.
Penny Nom lui répond.
Volume of a tank 2005-09-11
Jim pose la question :
We own an Rv and need to actually know the volume of our fresh water tank. I think I'm getting the run around from the manufacturer. I'm unable to locate my chemistry books from from collage. I know there is a formula for the volume of a rectangle some place.
Penny Nom lui répond.
A normal distribution problem 2005-08-08
Brad pose la question :
The life of a toy is normally distributed. Suppose 92.51% of the items lives exceeding 2,160 hours and 3.92% have lives exceeding 17,040 hours. Find the mean and the standard deviation.
Penny Nom lui répond.
Two tangents to a circle 2005-06-18
Tej pose la question :
The tangents drawn from points M and N of a circle having centre O intersect each other at point P. If angle MPN=60 degrees, NM=10, then find the radius of the circle and Area of quadrilateral OMPN.
Penny Nom lui répond.
Gallons in a tank 2005-04-02
Jim pose la question :
Would you be so kind as to help me with a problem? My memory has failed me in remembering how to calculate how much liquid in gallons a tank will hold. The tank is 8 feet long and 44 inches in diameter.
Penny Nom lui répond.
The integral of tan^4x 2005-03-31
Nicole pose la question :
college student. need help with tough integral.

the integral of 2tan4xdx


Penny Nom lui répond.
The shortest distance from a point to a line 2005-03-30
carly pose la question :
Find the shortest distance from the point (-15, 2.5) to the line 5x+6y=30.
Penny Nom lui répond.
Gasoline in a cylindrical tank 2005-03-23
Jennifer pose la question :

Gasoline is stored in a tank which is a cylinder on its side. Height of fuel is "h" meters and the diameter is "d". The length is "l".

I need to find the amount of gas in the tank when the height is h and also to calculate the fraction of how full it is.

Also, the part I am really confused on is this one,
E(h/d) is the error of the function of h/d, when h/d is used to measure how full the tank is. For what value of h/d is the error maximal?


Penny Nom lui répond.
Tangents to a circle 2005-03-19
Sue pose la question :

You're given the equation to a circle (x-3)2 + (y-3)2 = 4 and you need to do 3 things:
1. Find a point on the circle
2. Construct an equation for a tangent line to the circle and through the point
3. Plot the circle, point and the tangent line on one graph

Penny Nom lui répond.
The volume of a stock tank 2005-03-13
Cord pose la question :
I am a farmer and I have recently installed a new stock tank which is 1650" in circumference and 10' deep. How many gallons of water will it hold?
Penny Nom lui répond.
Three tangent circles 2005-01-25
Kate pose la question :
Two circles, C1 and C2, touch each other externally; and the line l is a common tangent. The line m is parallel to l and touches the two circls C1 and C3. The three circles are mutually tangent. If the radius of C2 is 9 and if the radius of C3 is 4, what is the radius of C1?
Chris Fisher lui répond.
Standard deviation 2005-01-02
Urial pose la question :
Find the standard deviation of the given data set
To get the best deal for CD dealer, Jessica called eight appliance stores and asked the cast of a specific model. The prices she quoted are listed below.

$300, $203, $272, $332, $440, $119, $129,$254

Penny Nom lui répond.
The gradiant of a hill is 9% 2004-12-18
Jim pose la question :
The gradiant of a hill is 9%. What angle is created by the run/rise of the hill and 0 degrees?
Penny Nom lui répond.
The tangent line at an inflection point 2004-11-28
Louise pose la question :
the equation of the tangent line to the curve y = x3 - 6x2 at its point of inflection is...
Penny Nom lui répond.
Is a square a rectangle? 2004-11-21
Carol pose la question :
I am a teacher. In an FCAT sixth grade review test, there was a question to the students to draw a square and then they referred to it as a rectangle.

What is the definition that makes a rectangle a square that can be taught to the students without confusing them.

Walter Whiteley lui répond.
A standard deviation test 2004-11-09
Karen pose la question :
How do you compare to see if a sample standard deviation is different than the population standard deviation? I know how to compare means, but not standard deviations.
Penny Nom lui répond.
The combined force of two vectors 2004-10-30
Brian pose la question :
Two teams are playing push ball with a large 8 foot diameter ball. One team exerts a force represented by the vector a = 2i + -5j, and the other team exerts a force represented by the vector b = -8i-3j.

1.Determine the direction of movement of the ball if the i axis is due east.

2.Determine the combined force magnitude.

Harley Weston lui répond.
The force of a 5000 tonne lorry 2004-10-27
Aaron pose la question :
A 50 tonne lorry is parked on a slope with a gradient of 4%. Due to the self weight of the lorry, what is the force

* acting down the slope
* acting normal (at right angles) to the slope

Penny Nom lui répond.
A rate of change problem 2004-10-15
Frank pose la question :
Find the rate of change of the distance between the origin and a moving point on the graph of y = x(squared) + 1 if dx/dt = 2 centimeters per second.
Penny Nom lui répond.
A common tangent line 2004-10-05
Shanup pose la question :
The x-axis is a common tangent of y = x^2 and y = x^3. Find the equation of another common tangent.
Penny Nom lui répond.
The length of a rectangle 2004-09-26
Rebecca pose la question :
My question is each side of a square S is 18 inches long and the area of S is at least 3 times the area of a rectangle that is 9 inches wide. What is the greatest possible length in inches of the rectangle?
Penny Nom lui répond.
Incremental variance 2004-09-23
Carlos pose la question :
I must keep statistical data (mean and variance) in 3 granularity levels depending on the age of the data (daily for older than 1 year, hourly for older than 1 month and quarter-hour for older than 1 day). How can I calculate the resulting variance from a set of variances previously calculated supposing I have the count and mean for each member of the set?
Andrei Volodin and Penny Nom lui répond.
The distance formula 2004-09-04
Joe pose la question :
Why do we use square roots and squares in the distance formula Wholdnt they cancel each other out?
Claude Tardif lui répond.
A tangent to a hyperbola 2004-08-02
A student pose la question :
The equation of a hyperbola is 32x*2 -18Y*2-64x +72y +248=0. The equation of a tangent line to this hyperbola is y= (16/15)X + 10/3 I have been trying to find the point where this line intersects the graph. What I did was solve for x and then plugged in the result into the equation of the hyperbola, but I am getting two answers and I am supposed to get only one because the line is tangent to the graph. For this reason, I would like to know what I am doing wrong or what I have to do to know which answer is correct.
Penny Nom lui répond.
Two vector problems 2004-07-14
Jaye pose la question :
Two force, 120lb and 200lb, act on a body and make a 52 degree angle w/ ea. other. What's the magnitude of the resultant of the forces and what is the measure, to the nearest degree, of the angle that it makes with the 200lb force?
Penny Nom lui répond.
The tangent of theta 2004-07-10
Jacob pose la question :
P is a point on a unit circle with coordinates(0.6,0.8). Find tan of theta. My book shows me how to do it,"tan of theta=opp./adj.=0.8/0.6=4/3,"and leaves it as that's the answer(4/3).When do we know from a problem to find the angle measure (in this case, the angle measure of theta) and how do we know when to give something like 4/3 without converting it to the angle measure?
Penny Nom lui répond.
What is the name of a 3D rectangle? 2004-06-07
Jack pose la question :
if a cube is a 3D square, what is the name of a 3D rectangle?
Penny Nom lui répond.
A tangent to a quadratic 2004-06-04
Jem pose la question :
I have a question on the tangent to a quadratic curve. Say I have a curve y = ax2 + bx + c. The gradient, using the derivative of y, at any point x on the curve is: 2ax + b right? Then, for the tangent that cuts the curve at a point x, the equation of the tangent can be: y1 = (2ax + b)x1 + d.

My question is, how is the point d of this tangent determined? It is the point on the y-axis where the tangent cuts isn't it? Is there a formula for it?

Penny Nom lui répond.
The center of a circle 2004-05-26
Wan pose la question :
I am trying to find the radius of an arc. The only things i know about the arc is all referenced from the line of tangency to the arc. on both sides i have a differnt horizontal perpendicular distance to the point of tangency. left side |-------*---------------| right side (*=point of tangency). Then i have 2 difference vertical perpendicular distance of the end points to the line of tangency. I know it sounds very bad in text but this is all i know about the arc. Can you help me find the radius?
Penny Nom lui répond.
How far apart are they? 2004-05-23
A student pose la question :
2 cars start at same loc. drive opposite direction for 6 miles then they each turn left and travel for 8 miles how far apart are they?
Penny Nom lui répond.
The dimsenions of a room 2004-05-18
Estella pose la question :
I have a room that is rectangular the area is 159.5 feet, the perimeter is 51 feet what would the dimensions of the room.
Penny Nom lui répond.
Area and perimeter 2004-03-12
Sandy pose la question :
The rectange has an area of M square units and a perimeter of 2M units. What is the value of x?

The length of the rectange is 3, while the width of the rectange is x-1.

Penny Nom lui répond.
Distance, time and rate 2004-03-09
Peter pose la question :
A car travels from one city to another at the speed of 32mph, if it had gone 4mph faster it could have made the trip in one half hour less. How far apart are the cities?
Penny Nom lui répond.
A geometry problem 2004-03-04
Jennifer pose la question :
I need help with this problem: Square ABCD has side length 2. A semicircle with diameter AB is constructed inside the square, and the tangent to the semicircle from C intersects side AD at E. What is the exact length of CE?o
Chris Fisher lui répond.
Volume of a fuel tank 2004-03-01
Mike pose la question :
I have a fuel ank for my big truck that has a radius of 24inches and a length of 65 inches. I am trying to compute the volume of fuel in the tank. I tried pie x the radius squared times the length but no usable results. Can you help me please?
Penny Nom lui répond.
The dimensions of a rectangle 2004-02-21
Jane pose la question :
A rectangular label has an area of 176cm2 and a perimeter of 54cm. Find the dimensions of the label.
Penny Nom lui répond.
A pyramid-shaped tank 2004-02-13
Annette pose la question :
The base of a pyramid-shaped tank is a square with sides of length 9 feet, and the vertex of the pyramid is 12 feet above the base. The tank is filled to a depth of 4 feet, and water is flowing into the tank at a rate of 3 cubic feet per second. Find the rate of change of the depth of water in the tank. (Hint: the volume of a pyramid is V = 1/3 B h , where B is the base area and h is the height of the pyramid.)
Harley Weston lui répond.
Driving from Sarnia 2004-02-11
Jane pose la question :
"Crystal drove from Sarnia at 80km/hr. Emily left Sarnia one hour later and drove along the same road at 100km/hr. How far from Sarnia did Emily overtake Crystal?"
Claude Tardif lui répond.
The London marathon 2004-01-27
Nina pose la question :
After a years training, Minnie Midriffe increased her average speed in the london marathon by 25%. By what percentage did her time decrease?o
Penny Nom lui répond.
Business trip 2003-12-19
Ameer pose la question :
A businnessman drives from Washington, D.C., to Boston, a distance of 442 miles, and then makes the return trip. On the way to Boston, he drives 65 miles per hour, taking an 1-hour rest stop during the drive. After finishing his business in Boston, he make the return trip driving at 60 miles per hour and takes a 45-minute rest stop halfway through the trip. Which leg of the journey, Washington, D.C. to Boston, or Boston to Washington, D.C., takes the longer time?
Penny Nom lui répond.
A fish tank 2003-11-26
Bill pose la question :
How do I work out the volume and weight of water in a fish tank that is 36in x 14in x 12in?
Penny Nom lui répond.
A point and a line 2003-11-19
Meenakshi pose la question :

Given a line segment L(x1,y1) to (x2,y2) and a Point P(x3,y3).
I need the formula to find a point on the line L that is closest to the point (x3,y3).


Penny Nom lui répond.
A rectangle on a disk 2003-10-29
Arthur pose la question :
How do I go about solving the following problem: What is the width of the largest rectangle with a length of 16 inches you can cut from a circular piece of cardboard having a 10 inch radius?
Penny Nom lui répond.
Squares in a rectangle 2003-10-21
Raj pose la question :

Draw a rectangle with sides of 3 and 4. Divide the sides into 3 and 4 equal parts respectively. Draw squares joining the points on the sides of the rectangle. You will have 12 small squares inside the 3 x 4 rectangle.

If you draw a diagonal of the rectangle, it will intersect 6 of the the 12 smaller squares.

Similarly, if you have a 4 x 10 rectangle, the diagonal would intersect 12 of the 40 squares inside the rectangle.

Is there an algebric equation that determines the number of squares that will be intersected by the diagonal of a rectangle?


Chris Fisher lui répond.
Statistics from grouped data 2003-10-09
Rebecca pose la question :

I have to use a suitable computer package (ie. Excel) to work out the mean and standard deviation of the following:

 Price Range            No of Houses        No of Houses 
£`000                  Area 1              Area 2   

45 and under 50         4                   5 
50 and under 55        7                   12 
55 and under 60        14                  16 
60 and under 70        19                  18 
70 and under 80        8                   3 
80 and under 100       5                   2 

I have used excel to work out mean and standard deviation before, but not in a more complicated example like this.

Any advice on where to start would be greatly appreciated.


Penny Nom lui répond.
Standard Deviation 2003-10-07
Rebecca pose la question :

I have a task to complete, which is to calculate the mean and standard deviation of something. I have done this but am then asked to write a short explanation of my findings.

I know what the mean is about, and I thought I knew what the standard deviation meant too - shows the variation from the mean. However, on a task I completed earlier the feedback I got said 'you need to tell us that it is talking about the middle 66% of the data' - that has thrown me, I don't understand that. Can anyone help me get my head round this???


Penny Nom lui répond.
The sketch of a graph 2003-10-07
A student pose la question :
I was wondering how do you figure out if a graph has a horizontal tangent line. One of my homework problem was to sketch the graph of the following function; (4/3)x3-2x2+x. I set f''(x) ( the second derivative) of the function equal to zero and got the inflection point:(1/2,1/6). Also i am having trouble finding the concavity for x>1/2 and x<1/2, i am getting a different answer from the back of the book, the graph i draw looks completely different from the correct answer.
Penny Nom lui répond.
The slope of a tangent 2003-10-01
A student pose la question :

find the slope of the tangent to each curve at the given point

f(x)=square root 16-x, where y=5


Penny Nom lui répond.
A rectangle in a circle 2003-09-27
Abdu pose la question :
A rectangle ABCD is inscribed in a circle. If the length of AB is 5 and length of BC is 12, what is the area of circle outside the rectanlge ABCD?
Penny Nom lui répond.
Notation 2003-09-15
Kim pose la question :

Question:
i have a couple of questions

1. write in standard form
a)4x2x8 b) 5 to the power of 4

.
.
.

Penny Nom lui répond.
Area of a rectangular room 2003-09-11
Kelly pose la question :
The area of a rectangular room is 238 square feet. The width is 3 feet less than the length. What are the dimensions?
Penny Nom lui répond.
A boat travels 12 km upstream... 2003-09-03
Sohaib pose la question :
A boat travels 12 km upstream and back in 1 hour 45 minutes. If the speed of the current is 3km/hr throughout, find the speed of the boat in still water, giving your answerÝcorrect to 3 decimal places.
Penny Nom lui répond.
Water in a tank 2003-09-02
A parent pose la question :
if a tank is 48 inches long 14 inches wide and 18 inches deep if a yardstick was inserted into the tank and measured 2 inches of water in the tank how many gallons of water would be in the tank.
Penny Nom lui répond.
A theorem in geometry 2003-09-02
Diego pose la question :
Please refer to figure in attached file. P is a point on the chord AB of a circle such that the tangent PT which touches the circle at T is equal to AB. How do we prove that PT2 = AP x BP.
Dieter Ruoff and Penny Nom lui répond.
A rule with a variable 2003-08-24
Crystal pose la question :
what is a rule with a variable
Penny Nom lui répond.
The volume of a fuel tank 2003-08-16
Phil pose la question :
I hope you can help me out with a small problem. My boat has a fuel tank measuring 1680mm long x 630mm wide x 130mm high. Can you tell me how much fuel it will hold in both litres and imperial gallons.
Penny Nom lui répond.
Two cars 2003-07-09
Nicole pose la question :
Two cars start off at the same point on a striaght highway facing opposite directions. Each car drives 6 miles, talkes a left turn, and drives for 8 miles. How far apart are the two cars.
Penny Nom lui répond.
Is 3/5 CLOSEST to 0, 1/2 or 1? 2003-07-09
A student pose la question :
I would like to know is 3/5 CLOSEST to 0, 1/2 or 1. And can 3/10 go either way as to be closest to 0 or 1/2.
Penny Nom lui répond.
The weight of a fish tank 2003-05-20
A ponderer pose la question :
I had a question pertaining conversion units..I have a fish tank at home and the dimensions are 24, 44, and 48 inches, I want to find out how much it weighs in pounds when filled up with water...knowing water is 62.4 pounds per cubic feet...do I just divide the 62.4 pounds to 12 because I"m trying to find out through cubic inches.
Penny Nom lui répond.
sin theta = 7/8 2003-05-07
Patty pose la question :
If sin0 = 7/8 and 0 is in quadrant 2, find the other five trigonometric functions of 0. (report your answers in radical form)
Penny Nom lui répond.
A circle, tangent to two circles and a line 2003-04-30
Keith pose la question :
I have a horizontal line (that is treated as a datum line or the X axis), with two circles having their center points at different heights from that line (X1,Y1 & X2,Y2). The two circles are also at different diameters (R1 & R2). Both circles and the line (X-Axis) do not intersect nor are they tangent. My goal is to determine the maximum diameter of an inscribed circle that will fit between all three.
Chris Fisher and Harley Weston lui répond.
A tangent to a circle 2003-04-18
Lech pose la question :
The line with equation y=mx is a tangent to the circle with equation x2+y2-6x-6y+17=0. Find the possible values of m.
Harley Weston lui répond.
Incremental standard deviation 2003-04-12
Carlos pose la question :
I need to calculate the standard deviation for a group of data, but I don't know in advance what is the mean. Is there a way to adjust the STDV for each datum without keeping all of the previous values? This is needed basicaly for performance, so I won't need to read twice the same data (spend processing time) nor save the previous values (spend memory).
Andrei Volodin and Penny Nom lui répond.
Can a square be considered a rectangle? 2003-02-27
Carla pose la question :

Can a square be considered a rectangle? (since opposite sides are same length and parallel)

Would a regular hexagon or octagon be considered a parallelogram since its opposite sides are parallel? or does a parallelogram HAVE to have only 4 sides?


Penny Nom lui répond.
Two airplanes leave Dallas 2003-02-06
A student pose la question :
TWO AIRPLANES LEAVE DALLAS AT THE SAME TIME AND FLY IN OPPOSITE DIRECTIONS. ONE AIRPLANE TRAVELS 80 MILES PER HOUR FASTER THAN THE OTHER. AFTER THREE HOURS, THEY ARE 2940 MILES APART. WHAT IS THE RATE OF EACH AIRPLANE?
Penny Nom lui répond.
A train with 2 cars 2003-02-04
Michael pose la question :
A train with 2 cars is traveling at a speed of 80 km/hr from town X to town y, located 800 km from each other. At the same moment that the train departed, a passenger started to walk back and forth from one end of car B to the other at a speed of 100cm/sec. Arriving in town Y, the passenger had already gone and returned 720 times. The length of car A is that of car B plus one fourth of the length of the locomotive, and the length of the locomotive equals the length of Car A plus one fifth of the length of car B. What is the total length of the train?
Penny Nom lui répond.
A rectangular prism 2003-01-09
Julie pose la question :
How many faces on a rectangular prism and how many bases? Can the base also be a face and can a face also be a base?
Diane Hanson lui répond.
Trigonometry problems 2002-12-01
Chiara pose la question :
  1. Find tan 35pi/4
  2. Graph y = cos2x - 2sinx

Penny Nom lui répond.
Constructing a tangent to two circles 2002-11-28
Tom pose la question :
I have two circles, different sizes a known distance from each other. We know the radii of the circles. How do I construct a line that is tangent to both circles relative to the segment that connects the centers of both circles?
Chris Fisher and Penny Nom lui répond.
Miles per hour 2002-11-28
Liz pose la question :
If a car has traveled 16 miles in 30 minutes, how many miles per hour did they go?
Penny Nom lui répond.
Two tanks of water 2002-11-08
A student pose la question :
A 2000 L tank containing 550 L of water is being filled with water at the rate of 75 L per minute from a full 1600 L tank. How long will it be before the two tanks have the same amount of water?
Penny Nom lui répond.
Variance 2002-10-29
Ade pose la question :
I am trying to solve a standard deviation question, I have 30 data points to use, should I group the data before solving for variance or should I just use the raw data.
Andrei Volodin lui répond.
Is a square a rectangle? 2002-10-20
Nona pose la question :
Are squares rectangles? Third grade math teacher told a student this was true. Grandmother needs confirmation on this!
Claude Tardif and Harley Weston lui répond.
How long will it be before you reach your friend? 2002-09-16
Margaret pose la question :
Your friend runs at 8 miles per hour and you drive at 40 miles per hour, hence the diatance between you is decreasing at 32 miles per hour. You firend left 2 hours before you so how far has he gone in that 2 hours? How long will it take for the distance between you to decrease to 0 miles if the distance is decreasing at 32 miles per hour?
Penny Nom lui répond.
The tangent to a curve and the tangent of an angle 2002-08-26
A teacher pose la question :
Is there a relationship between the tangent of a curve(line touching the curve at one point) and tangent (the trigonometric function)?
Chris Fisher lui répond.
Distance in 3-space 2002-08-16
David pose la question :
The question is: how do I figure out the distance of one object in 3D space to another object in 3D space? I have an object at say x = 5.872, y = 2.876, and z = 7.290; and the other object is at x = 1.129, y = -8.213, and z = -11.127. I have been suggested to use the pythagorean theory on this, but since there are three variables, I don't understand how.
Penny Nom lui répond.
Two equations 2002-07-26
Derek pose la question :
1. 3x + 2y = 4
2. -7x + 2y = 24

finding x and y.


Penny Nom lui répond.
Bob swam across a river 2002-05-22
Torri pose la question :
Bob swam across a river 420 ft wide. A strong current carried him 580ft downstream as he swam. Find x, the distance bob actually swam.
Penny Nom lui répond.
Day care 2002-05-13
Sonam pose la question :
In many familes, both parents work. as a result, there is increasing need for day care. data was collected; and in one year in Canada, approximately 32% of children aged 0 to 11 years were in day care for at least 20h per week.

(a) what is the probability, in a random poll of 60 children form the age of 0 to 11, that more than 15 children are in day care at least 20 h per week? nearest tenth of one %

ANSWER:
P(children are in daycare at least 20h)= 60/60C14 = to the answer

(b) what is the probability, in a random pool of 60 children that fewer than 20 are in day care at least 20 h per week?

ANSWER:
P= 20/60= 33.3% stay in day care for 20h per week,

I dont know if these answers are right please help me out.


Andrei Volodin lui répond.
Trains and cracker boxes 2002-04-29
Lindsay pose la question :
1)Two trains are 250 miles apart on the same track heading towards eaxh other at 7AM- The first train travels at 55mph, the second at 75mph. At what time would they crash?

2)A cracker box measures 12 by 2 by 18 inches. The company wants to double the amount of crackers, but keep the shapes the same[similar] Find the new length[nearest tenth of an inch]


Penny Nom lui répond.
A test drive 2002-04-23
Jennie pose la question :
At 9 A.M. a test car driving at a constant speed passes a marker 50 miles from it's starting point. At noon the car is about 130 miles from the marker. If the test drive ends at 1:30 P.M., how far will the car be from its starting point?
Penny Nom lui répond.
Pairs of equations 2002-04-04
A student pose la question :

high school level
student is asking

y=4x x=-4y 
x+y=5 3x+2y=20   

y=x-1 3x-y=4 
x+y=3 2x-3y=-9   

x+5y=4 
3x+15y=-1 

. . . 

Penny Nom lui répond.
Range of values for standard deviation 2002-03-22
Susan pose la question :
What is the range of values for standard deviation? Is it between 0 and +3? Is it between +1 and +3?
Andrei Volodin lui répond.
15 miles at 13 miles per hour 2002-03-12
Rich pose la question :
If I were traveling 15 miles at 13 miles per hour how long will it take?
Penny Nom lui répond.
The slope of a tangent line 2002-03-04
Ridley pose la question :
Suppose a function f(x) has the line 3x+4y=2 as its tangent line at x=5. Find f'(5).
Harley Weston lui répond.
Two circles inscribed in a rectangle 2002-02-27
Amina pose la question :
Given a rectangle with dimensions L=6, H=5. Two circles are inscribed such that they touch each other(circles are adjacent to each other) and also their circumferences touch 2 sides of the rectangle. One of the circles has radius=4. Find the radius of the other circle.
Penny Nom lui répond.
The substitution method 2002-02-24
Joe pose la question :
whats the answer to this question? 3x+y=11
x+2y=-3

its substitution method i am having alot of trouble figuring it out. send the answer as soon as possible. thank you


Penny Nom lui répond.
Can the standard deviation ever = 0? 2002-02-16
Karen pose la question :
If given a class of 30 people who take a test with a mean of 80. Can the standard deviation ever = 0? If so, why?
Penny Nom lui répond.
Normal distribution 2002-01-21
Danielle pose la question :
A teacher gave a test on which the students' marks were normally distributed, but the results were pathetic. The mean was 52% and the standart deviation was 12%. The teacher decided that the top 10% of the students should get A's, the next 20% should get B's, the next 40% should get C's, the next 20% should get D's, and the bottom 10% should get F's. To the nearest percent, what are the cutoff marks that will result in an A, B, C, D, and F?
Penny Nom lui répond.
The distance across a circle 2002-01-18
Douglas pose la question :
If you know how far around a circle is (say earth) 25000 miles how do you calculate the distance across?
Penny Nom lui répond.
The tangent function 2002-01-12
Justine pose la question :
if you know that sin45degress = cos45degrees, how do you know that tan45degrees = 1?
Penny Nom lui répond.
The famous "train problem" 2002-01-12
Karen pose la question :
How do you solve the famous "train problem"? For example, 2 trains leave different stations at the same time. One is traveling at 50 mph and the other at 40 mph. How long does it take them to meet?
Penny Nom lui répond.
Simultaneous equations 2001-12-17
Matthew pose la question :
4x + y = 4
2x - 3y = 5

what is x and y


Penny Nom lui répond.
Two equations in two unknowns 2001-12-04
Courtney pose la question :
y = 3x + 2
y = 4x - 5

solve for x

Penny Nom lui répond.
Undetermined coefficients 2001-11-22
Hoda pose la question :
The equation is:

y" - 2y' + y = t et + 4

We need to use The method of Undetermined coefficients. I have tried assuming that the solution is Atet+Bet+C, but all I get is C=4 and I tried (At2+Bt+C)et+D, but again I get 0=0 when I calculate the first and second derivatives, so i get no information on the constants. Any suggestions?


Harley Weston lui répond.
A tangent line 2001-11-21
A student pose la question :
write an equation of the line tangent to the graph of

ey + ln(xy) = 1 + e at (e,1)

Harley Weston lui répond.
Area of a quilt 2001-10-14
Jack pose la question :
  1. how would you find the area of the quilt? which is a square

  2. how would you fined the area of each square?

Penny Nom lui répond.
Joan and Jan work together 2001-09-26
Karyna pose la question :
Joan and Jan work together and they set up a bandstand in just 24 minutes, but if Joan does it by herself she takes 1 hour. How long would it take Jan to set up the bandstand by himself?
Claude Tardif lui répond.
Julia goes to work 2001-09-25
Karyna pose la question :
On one October morning, Julia rides her bike (at 12 miles per hour) from her home to her friend Ida's house; then the two of them walk (at 6 miles per hour) to work. If it takes an hour for Julia to go the 10 miles from her home to work, how far does she walk?
Penny Nom lui répond.
Ciefficient of variation 2001-09-23
Carmen pose la question :
I have a question from my OAC finite class. I've come across a problem with the coefficient of variation. I have taught my students that there are no units for coefficient of variation and it can be expressed as a percent. So, for example, a set of data with mean of 5 and standard deviation of 100 would have a CV of 5%. But what happens in this situation: the mean is 4meters and the standard deviation is 0.7mm. Is the CV 1.75% or 0.00175% or 0.0175%? I've had some students change leave the units as is, change them both to mm or change them both to meters...so which is it and why?
Penny Nom lui répond.
Standard deviation 2001-09-22
Doug pose la question :
I was wondering if anybody knows who the founder of standard deviation was?
Penny Nom lui répond.
Ray and Jane 2001-09-06
A student pose la question :
If Ray and Jane live 150 miles apart and they both leave their house at the same time, Ray goes 30 mph the whole time and Jane goes 50 mph the whole time how many miles are they from Ray's house when they meet? And what is the exact travel time untl they meet.
Penny Nom lui répond.
Joe and his dad 2001-08-28
Sarah pose la question :
Joe Spout left a campsite on a trip down the river in a canoe, traveling at 6 km/h. Four hours later, Joe's father set out after him in a motorboat. The motorboat traveled 30 km/h. How long after Joe`s father started did he overtake the canoe? How far had Joe traveled down the river when his father overtook him?
Leeanne Boehm lui répond.
Standard angles 2001-08-05
Nagaraj pose la question :
Why 0o , 30o , 45o , 60o ,and 90o are taken as standard angles in Trigonometry? Why can't we take some other angles as standard angles?
Chris Fisher lui répond.
Linear regression 2001-08-01
A student and a mother pose la question :
My mom is taking a correspondence course in Simple Linear Regression and Correlation Analysis and we've been arguing about the relationship between the correlation -rxy and standard estimate of error-Sy.x. I took statistics last year in high school and I remember something about the Sy.x being proportionate to the r. Are they inversely related, directly related, not related, or can only range from 0 to 1.00? Her book doesn't say very much and I believe they are inversely related. She says they're directly related.
Chris Fisher and Penny Nom lui répond.
A trig identity 2001-07-27
Jeff pose la question :
prove this identity and show steps
tan(x/2+pi/4)=secx+tanx

Harley Weston lui répond.
Comparing means and standard deviations 2001-07-11
Shelly pose la question :
Is there a way to compare means and standard deviations that come from different size samples? Is there an equation that can normalize sample size?
Andrei Volodin lui répond.
Three tangents to a circle 2001-06-27
Stephanie pose la question :
The three lines PS, PT, and RQ are tangents to the circle. The points S, X, and T are the three points of tangency. Prove that the perimeter of triangle PQR is equal to 2PT.
Chris Fisher lui répond.
The shortest distance from a point to a line 2001-06-05
Kat pose la question :
Find the shortest distance from the given line. Round to the nearest tenth. (-2,-1) and x+5y+20=0
Penny Nom lui répond.
Common solution 2001-06-02
Samantha pose la question :
  1. Solve for common solution: x+y=6 2x-3y=2

  2. Solve for y in terms of x: 3x-y=4

Penny Nom lui répond.
Squares on a chess board 2001-04-11
Tom pose la question :
It was once claimed that there are 204 squares on an ordinary chessboard (8sq. x 8sq.) Can you justify this claim? "PLEASE" include pictures.

How many rectangles are there on an ordinary chessboard? (8sq. x 8sq.) "PLEASE" include pictures.


Penny Nom lui répond.
Prisms 2001-04-10
A fourth grade class pose la question :
A fourth grade class is curious about the names that have been given to various solid geometric figures based on their shapes: are there names for solids based on a rhombus, a trapezoid, a parallelogram, a decagon, and/or a quadralateral?
Chris Fisher lui répond.
The normal to a curve 2001-04-08
Varenne pose la question :
I am having SO much trouble tackling this question and don't know what the right answer is... can you help me out? The question is

Find the equation of the normal to the curve y=(x-2)2/(1-x)2 that is parallel to the line x+4y+7=0

Harley Weston lui répond.
Common tangents 2001-04-08
Anne pose la question :
I have been working on this problem for a while but I'm not sure I'm getting the right answer: Find the common tangents of 2y=x2 and 2y=-x2-16 Thanks for the help. :)
Harley Weston` lui répond.
Where do the lines y=2x-4 and y=x-1 intesect? 2001-04-06
Bryce pose la question :
solve the following problem by setting them equal to each other. Solve for x and y. Where do the lines y=2x-4 and y=x-1 intesect?
Penny Nom lui répond.
The unit circle and trigonometry 2001-04-05
Ashley pose la question :
"My teacher wants us to find out what a unit circle is, which I found out, a circle with the radius of 1, but the problem is he wants us to show the relationship between the unit circle and the sine(30,45,60 degrees), cosine(30,45,60 degrees),and tangent ratios(30,45,60 degrees). I need help with this and my teacher will not help us out. Thanks very much ...
Penny Nom lui répond.
Sigma 2001-03-31
A student pose la question :
What does the Sigma symbol mean in mathematics?
Penny Nom lui répond.
Systems of equations 2001-03-16
joy pose la question :
How do u solve problems using systems of equations?
~ finding x and y~

ex:

26 = 3x - 2y
42 = 4x + y


Penny Nom lui répond.
The angle of elevation 2001-03-08
Jeffrey pose la question :
At a Certain time, a vertical pole 3m tall cast a 4m shadow. What is the angle of elevation of the sun?
Harley Weston lui répond.
The substitution method 2001-03-05
A student pose la question :
Solve each system of equations by the substitution method. Show your work.
  1. y = 8
    7x = 1 - y

  2. y = x - 1
    4x - y = 19

Penny Nom lui répond.
A problem with distance 2001-01-16
A student pose la question :
For what values of a is the distance between P(a, 3) and Q(5, 2a) greater than the square root of 26.
Penny Nom lui répond.
cot(arcsin 3/5) 2001-01-07
Jason pose la question :
Find value. Assume that all angles are in Quadrant 1.

cot(arcsin 3/5)


Harley Weston lui répond.
Filling a tank 2001-01-02
Liting pose la question :
Water flows into a rectangle tank which measures 4 m by 3 m by 2.8 m through a cylindrical pipe of radius 2.4 cm. If the rate at which the water flows into the tank is 8 km/h, find how long it takes to fill the tank.
Penny Nom lui répond.
The aspect ratio of a rectangle 2000-12-04
Ron Delavigne pose la question :
The aspect ratio of this rectangle is 4:3. That is A to B is 3. And B to C is 4. If I know the lenght of A to C is 19 inches, how can I find the length of A to B, and B to C.
Penny Nom lui répond.
Triangles and trigonometry 2000-11-30
Mose pose la question :
If I have a right triangle, and I know the lengths of all three sides, is there a formula that will allow me to determine the measurements of the 2 non right angles?
Harley Weston lui répond.
Connecting to a water line 2000-10-20
Vanja pose la question :
My question is...A house is to be connected to a new water main that runs along the line y=2/3x-1. The connection point at the house has coordinates (2,9), where the units represent metres. What lenght of plastic pipe is needed to connect to the water main at the closest point?
Penny Nom lui répond.
Two linear equations 2000-09-14
David Dean pose la question :
2a + 1b = 3.39 3a + 3b = 6.59
What formula do I use to find what a = ?

Harley Weston lui répond.
Two geometry problems 2000-09-09
Becky pose la question :
What are all the real values of x that are solutions for the inequality [x-2] < 6? ( it's less than or equal to)

What is the distance between the points with (x,y) coordinates (3,-2) and (-3,-1)?


Peny Nom lui répond.
Euclidean distance 2000-09-06
Velma Zahirovic-Herbert pose la question :
If d(x,y) is euclidean distance between x and y Prove that
d(x,y)>=0
if d(x,y)=0 than x=y
and d(x,y)=d(y,x)

Paul Betts lui répond.
A trig question 2000-07-01
Will pose la question :
An open rectangular tank a units deep and b units wide holds water and is tilted so that the base BC makes an angle theta with the horizontal. When BC is returned to the horizontal, who that the depth of the water is

(a squared) * cot theta div 2b units


Harley Weston lui répond.
Parallel tangents 2000-06-30
Ebony Indalecio pose la question :
I need to prove the theroem: Tangents to a circle at the end points of a diameter are parallel.
Walter Whiteley lui répond.
Rectangles and algebra 2000-06-13
Kirstin pose la question :
A rectangle's length is 4 more than twice its width. The area of the rectangle is 336m squared. What is its length?
Paul Betts and Penny Nom lui répond.
A centroid problem 2000-06-02
Kerstin pose la question :
An isoceles triangle has sides measuring 13 cm, 13 cm, and 10 cm. Find the distance from the centroid to the vertex of a base angle.
Harley Weston lui répond.
A conic in standard form 2000-05-18
Tara McConkey pose la question :
Im havign trouble converting the following conic to standard form, i know that the conic is a hyperbola but that is all 16x2-9y2-160x-18y+247=0
Harley Weston lui répond.
Sample variance 2000-04-16
Jonathan Freeman pose la question :
I was just reading your article entitled "A Note on Standard Deviation" I'm now teaching a unit on s.d. and my students were wondering why one uses a denominator of n for a population and n-1 for a sample. I saw in your article that this is because "[the quantity] tends to underestimate sigma... and other technical reasons." To which my students again asked... "Why?" Could you please elaborate a bit on the "other technical reasons" perhaps in terms a high school senior (or their teacher...) could understand?
Harley Weston lui répond.
A parabola problem 2000-03-23
Morin pose la question :
I need to prove that if parabola x2=4py has a chord (not necessarily a focal chord) intersecting it at points A and B, with tangents to the parabola at points A and B that intersect at C, then a line drawn through C and the midpoint of the chord M is parallel to the y-axis. Further, prove that the point D where this line intersects the parabola is the midpoint of line CM.
Penny Nom lui répond.
Simultaneous equations 2000-03-11
Laura Molck pose la question :
My name is Laura Molck and I am in Year 11 in Australia. Please help me with the following. I know that they are all simultaneous equations which I can do but I have trouble with the formulae to work the equations. Can you please help!!

1. A tent manufacturer produces 2 models, Outback and Bushwalker. From earlier sales records it is known that 20% more of the Outback model is sold than the Bushwalker. A profit of $200 is made on each Outback sold, but $350 is made on each Bushwalker. If during the next year a profit of $177,000 is planned how many of each model must be sold?


Penny Nom lui répond.
Systems of linear equations 2000-03-10
Ann Marie Devereux pose la question :
hi there!!, I guess I have a problem!!!
  • 3x+4y=10 (over)
    4x+y=9

  • 2x=5y+3 (over)
    x=3y+1


Penny Nom lui répond.
Angle of Intersection of Two Lines 2000-03-02
Veronica Patterson pose la question :
I am having a real hard time trying to figure out this problem. Could you please help me! The homework question says to find the acute angle of intersection between the two lines y=3x+1 and y=(1/2)x-1. (It also says to use the results of a problem I had already figured out.) That problem was to use information from a picture shown that tan(theta sub1-theta sub2)= ((m sub2- m sub1)/(1+(m sub1 * m sub2))). I used the difference identity of tangent to figure out the answer. Any help on this problem would be greatly appreciated.
Harley Weston lui répond.
Is a square a rectangle? 2000-02-15
Jaireh pose la question :
This is something that aroused a debate in class: A rectangle was defined as a parallelogram with 4 right angles. A square was defined as a parallelogram with 4 congruent sides and 4 right angles.

I need written and conclusive proof that some rectangles can or cannot be squares. I tried insisting that some of them can.. but without proof nobody will listen.


Walter Whiteley lui répond.
Taxicab geometry 2000-01-16
Jack pose la question :
Im doing an investigation entitled 'taxicab geometry', ive attempted it and have done most of the practical part of it. But i cant seem to see the equation behind it all. please guide me in the right direction.

They provide a regular grid with regular horizontal and vertical lines. The lines are roads and the actual squares are blocks of hoouses/ buildings.

In taxicab geometry the distance between place A & B is worked out by adding together the horizontal and vertical distances. each square is counted as i unit.

Part 1 (I've done this)

A taxix cab firm is based at A. the posistion B is 7 units away from A. investigate all the posistions of B at 7 units. investigate for different distances.

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Penny Nom lui répond.
Three dimensional rectangle 2000-01-11
Dennis Murphy pose la question :
I would like to find out the name of a Three dimensional rectangle.
Harley Weston lui répond.
Rectangular hyperbola 1999-12-15
Aarti Chand pose la question :
Why do they call a rectangular hyperbola, rectangular and where the normal hyperbola looks like a rectangle and the rectangular hyperbola looks like a sqaure?
Chris Fisher lui répond.
Systems of equations 1999-12-06
Roger Hornbaker pose la question :
I am having problem figuring out x and y solutions.
  1. 5x + y = 4
    3x - y = 4

  2. 3x + 2y = 6
    - 3x + y = 0

Penny Nom lui répond.
An area problem 1999-11-29
Vicky Birch pose la question :
The length of a rectangle is three times it's breadth. If the length were 6 meters less, and the breadth were 6 meters more, the rectangle would be a square. Make a mathematical model and solve the resulting equation to find the breadth of the original rectangle. What is the area of the square?
Penny Nom lui répond.
Estimating the population mean 1999-11-13
John Barekman pose la question :
Statitistics: Estimating the population mean when the standard deviation is known:

I am not sure which n to use in the formula for the confidence interval equation:

x +/- z*(standard deviation/sqrt(n))

If we have data of ten people, and if we have the data of ten sets of ten people each, what is the difference in the n that we use? What is the difference between the standard deviation and the standard error? Are we using the number of sampling means or just the number of samples?
Harley Weston lui répond.

Distance between the windows 1999-09-19
Lawrence pose la question :
An observer on level ground is at distance d from a building. The angles of elevation to the bottom of the windows on the second and third floors are a and b respectively. Find the distance h between the bottoms of the windows in terms of a b and d
Harley Weston lui répond.
Standard Deviation 1999-07-11
Anthony Fama pose la question :
I have seen several answers to this question: If one standard deviation represents 68% of the population, what does two, three, four and five sigma [std deviation] represent? As stated, I have seen several different answers and thus, the impetus for my question.
Harley Weston lui répond.
Girth 1999-05-26
Carolyn Bulkley pose la question :
I am trying to explain to my son (who is in the 8th grade) how to figure girth. I'm afraid I have just confused him. Is there a simply formula to figure the girth of a box.

for example: I have a box that is 27" L X 22" W X 21" H.
Penny Nom lui répond.

A bike race 1999-04-23
Bill Gepford pose la question :
Bill was in a bike race and his friend kyle calculated that if he went 15mph that he would cross the noontime checkpoint one hour early but if he rode 10mph he would arrive one hour late.
How far away is the checkpoint?

Penny Nom lui répond.
Universal Area 1999-04-08
Karen Richardson pose la question :
I need a formula for area that works for a square, a rectangle, a parallelogram, a trapezoid, and a triangle.
Jack LeSage, Chris Fisher and Harley Weston lui répond.
Standard Form 1999-03-30
Pam pose la question :
How do you put this equation into standard form?

y=3.572x+5.409

Would you please put this equation in this form Ax+Dy+C=0
Penny Nom lui répond.

An airplane problem 1999-03-08
B.M.R. pose la question :
A plane left New York and headed East to its destination 3600 miles away across the Atlantic. On the way back its speed was boosted by a 50 mph tail wind and it arrived an hour early. What was its normal speed?
Jack LeSage lui répond.
Absolute value of i 1999-01-06
Wayne Bagley pose la question :
I would like to know what is the absolute value of i. I need an answer suitable for the secondary level.
Harley Weston lui répond.
Two Chords 1998-09-29
Jennifer Cane pose la question :
Question:
two parallel chords of a circle, AB and CD, have lengths of 10 cm and 17 cm respectively. The diameter of the circle is 21 cm. Find the shortest distance between the chords.

Harley Weston lui répond.
Nickles on the Highway 1998-09-22
Ronnie Mac Donald pose la question :
How many nickels would it take to cover 226km of highway,each nickel is 2cm in diameter?
Penny Nom lui répond.
Area and Volume 1998-07-28
James Pulver pose la question :
I am going into 12th grade and am practicing for the SAT II. I have come across a problem that I cannot solve. It states that the front, side , and bottom faces of a retangular solid have areas of 24 square centimeters, 8 square centimeters, and 3 square centimeters, respectively. What is the volume of the solid. I need to know how to solve similar problems so is there a formula to go from area to volume?
Jack LeSage lui répond.
Trigonometry history 1998-05-26
Joeseph Huckler pose la question :
Can you please tell me some history of the trigonometric ratio Tangent? who discovered it? when was it discovered and some other useful info...
Penny Nom lui répond.
Mean and Standard Deviation 1998-04-22
Kit pose la question :
i have a problem of maths.
i think the level of the question is secondary. question: Find the mean and the standard deviation of the numbers:1, 3, 4, 5, 7. i hope u solve this question.
thank you so much!

Harley Weston lui répond.
Tangrams 1998-02-24
Allison pose la question :
Do you know the story behind the tangram? I know that it is a Chinese puzzle about 200 years old. If there is a story about its creation, I would love to share it with my 7th graders. Thanks.
Diane Hanson and Penny Nom lui répond.
Octants 1997-11-10
Jason Watkins pose la question :
I know which octant is octant 1 because all variables are positive. How do we number the other octants?
Harley Weston lui répond.
The Length of a Chord. 1997-07-26
Nathan Arthur pose la question :
Picture a 9 inch diameter circle. Inside that circle is a 6 inch diameter circle tangent to it. Then, tangent to both circles is a 3 inch diameter circle. So there are three circles, two smaller ones inside a big one, all of them just touching but not overlapping.

Now picture a chord on the 9 inch circle that is created by making a line that is tangent to both the 6 and the 3 inch circles and extending it to the edge of the 9 inch circle.

I need the length of that cord.
Chris Fisher lui répond.

The angle between two tangents. 1997-06-09
Felix Ho pose la question :
Two tangents are drawn from the origin to the circle (x)(x)+(y)(y)-4x-6y+9=0. If the angle between the tangents is m, fine the value of tan(m).

P.S. (x)(x)=square x
Harley Weston lui répond.

A trig problem 1996-12-13
S. Johnson pose la question :
sin t + cos t = 1/5. Find ALL exact values of cot t, given the original equation.
Harley Weston lui répond.
Height of a Hotel 1996-11-07
Irene pose la question :
"Irene" is to determine the # of floors in a hotel 500 feet up the street. Irene is on the 10th floor of an office building and can measure the angle of elevation to the top of the hotel, 57 degrees. Her view of the entire building is obstructed. If the street rises at an angle of 8 degrees from the office building to the hotel and the average distance between floors is 11 feet, how many floors are on the hotel?
Penny Nom lui répond.
A tangent to a circle is perpendicular to the radius at the point of contact. 1996-10-22
Rita Leung pose la question :
I wonder if there is any proof for this theorem - A tangent to a circle is perpendicular to the radius at the point of contact. If there is any proof for that, can you tell me please?
Chris Fisher and Harley Weston lui répond.
 
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