







1242, 826, 1034, 930, 1658 
20050831 

Elizabeth pose la question : here is a math question my niece gave me, grade 7
1242, 826, 1034, 930, 1658
first day of school and this is what they give her no explanation Harley Weston lui répond. 





1,4,9,1,6,2,5,3,6,4,9,6,4,8,1 
20050830 

Liz pose la question : Find the next four numbers to the sequence 1,4,9,1,6,2,5,3,6,4,9,6,4,8,1,___,___,___,___. Penny Nom lui répond. 





cos x * cos 2x * cos 4x * cos 8x 
20050829 

Leandro pose la question :
A = cos x * cos 2x * cos 4x * cos 8x
What's the value of log A at base 2?
Chris Fisher and Penny Nom lui répond. 





The area of a lot 
20050829 

Richard pose la question : My wife and I are interested in buying property in Idaho but the owner can't give us a square footage of the lot. The dimensions are as follows:
121.0 on the left side
157.0 on the right side
135.0 on the bottom
162.0 on the top
The bottom right corner of the lot is a true right angle, the rest are not. Penny Nom lui répond. 





The length of a lot 
20050828 

Billy pose la question : If I have 3 acres and the front is 300 ft across how many feet would I go down the sides to equal 3 acres? Penny Nom lui répond. 





1_2_3_4_5_6_7_8_9 = 1: Fill in the blanks 
20050826 

James pose la question : Try to replace the blanks below with + or  to make the statement correct
1_2_3_4_5_6_7_8_9 = 1 Penny Nom lui répond. 





Graphing a linear inequality 
20050826 

Gina pose la question : When graphing a linear inequality, how do you know if the inequality represents the area above the line? Penny Nom lui répond. 





y = log(x) + x. Solve for x. 
20050826 

Alain pose la question :
I have the following equation:
y = ln(x) + x
How do I solve for x?
Penny Nom lui répond. 





The area of a triangle 
20050826 

Martha pose la question : I have a triangle that with a base of 60' and the two sides of 37'. I know the formula for area is A=1/2 (b*h) but how do I find the height??
Penny Nom lui répond. 





The area of a pentagon 
20050824 

Susan pose la question : I need to calculate the square footage of a regular pentagon (all angles are equal). Each side is 16 feet long. Penny Nom lui répond. 





Labour efficiency 
20050823 

Rob pose la question :
The problem, on the surface, seems very simple and yet has created some controversy among a group of accountants. The problem itself has to do with labour efficiency rates and only involves two variables; standard working hours, and actual working hours. The difficulty lies in deriving an efficiency % from these two numbers.
Standard working hours or the targeted number of labour hours required to produce one widget, which I will represent as "s". Actual working hour or the actual number of labour hours require to produce one widget, which I will represent as "a". Labour efficiency I will represent with "E". The prevailing calculation with which I have a problem with is this:
s/a=E or if s=3000, and a=4000 then 3000/4000=75%
What bothers me about the calculation is that the standard hours get represented as a percentage of the actual hours and in my opinion changes the focus of the calculation from standard or target, where it should be, to the actual hours. I cannot define why, but this just seems inherently wrong to me.
The calculation that I use:
(1+((sa)/s))=E or if s=3000, and a=4000 then (1+((30004000)/3000))=66.67%
My calculation is like a %change from standard calculation. However, there is something that also concerns me about my calculation.
If you substitute 100 for a and 50 for s, then you come to a quandary, because if you plug those numbers into the second equation the result is of course zero % efficient which doesn't sit right with me either. If you plug them into the first calculation you get 50% efficiency which doesn't really seem to work either, because you require 100% more hours to do the same work in this case. ???
Is the first calculation correct? Am I missing something altogether? Are both calculations off base? Harley Weston lui répond. 





The range of a function 
20050821 

Kelsey pose la question : What is the range of the function f(x) = 4x  6 when the domain is {3,1,1,3,5}? Penny Nom lui répond. 





Fran goes to college 
20050821 

Thomas pose la question : Fran will begin attending longview college 1 year from now and will attend for the next 4 years. Her annual cost will be $14,000.00 which her parents have agreed to pay. Frans parents have saved enough money to meet Frans needs. How much must they invest in an account paying 10% interest compounded annually in order to receive $14,000.00 at the end of each of the next 4 years, having nothing left in the account at the end of that time? Penny Nom lui répond. 





Their sum equals their product 
20050821 

Claudio pose la question : Find a thousand natural numbers such that their sum equals their product. Penny Nom lui répond. 





3A/4 +1=(2A1)/3 
20050821 

Rachael pose la question :
I'm doing a practice test question and the answer I keep turning out is different from the answer on the answer sheet. I think I might be forgetting a step. The problem is:
3A/4 +1=(2A1)/3
The answer is 16. If anyone could explain the steps to me to getting the answer I would be grateful. Whenever I do it I get something completely different.
Penny Nom lui répond. 





The area of an octagon 
20050821 

A student pose la question : Hi I am a ninth grade student trying to figure the area of an octagon with sides of 4 feet and another one with sides of 5 feet Penny Nom lui répond. 





Can one place 15 integers around a circle... 
20050820 

Hernan pose la question : Can one place 15 integers around a circle so that the sum of every 4 consecutive numbers is equal either to 1 or 3? Claude Tardif lui répond. 





The radius of an arc 
20050819 

Jared pose la question : I need to be able to calculate the radius of an arc on an existing structure (Supports for Fifth Ave Dimensional Text). I have the overall length of this structure, but, the complication I believe lies in the fact that it is a curve mounted onto a flat section of wall on either side of a very mild curve, therefore, measuring the middle of the wall to the top of the arc does me little good...The reason I need this is to be able to replicate the above curve on a similar structure to be mounted below it...Also, because the client wants the structure mounted on the inside of the opening below the existing, the beginning and end point of the new structure would be lower than the existing, so, I do not believe that it is possible to exactly replicate the radius of the above curve? Penny lui répond. 





Which number is greater? 
20050818 

Dante pose la question : Which number is greater: 888....88 X 333...33 or 444.......44 x 666........67 (each of the numbers has 1989 digits)? Claude Tardif lui répond. 





Three days interest on one million dollars 
20050818 

Teresa pose la question : how much money is 3 days interest on one million dollars? Penny Nom lui répond. 





The volume of the earth in gallons 
20050818 

Daniel pose la question : I would like to know how to find the volume of the Earth in gallons. Penny Nom lui répond. 





Sample variance 
20050817 

Rosalie pose la question : To give an unbiased estimate of the population variance, the denominator of the sample variance should be (n1) instead of n. I tried to convince myself by comparing the population variance and sample variance (with denominator n and n1): Penny Nom lui répond. 





My fantasy football league 
20050816 

Jim pose la question : I have to make a schedule for my fantasy football league. There are 10 teams in the league and we play a 13 week season. The challenge is we want to play each team only once during the first 10 weeks. This way no team will play another team twice without having played each team at least once. Is this possible? Penny Nom lui répond. 





Hat size 
20050816 

Keshia pose la question : What formula would I use to find the measurement of a hat size? Ex. If the hat was 7 3/4", what formula would I use to get that measurement? Penny Nom lui répond. 





Is this percentage change or percentage increase? 
20050815 

Betty pose la question : When calculating a percentage, if the formula is
A(new)  B(old)/A(new)
Is this percentage change or percentage increase? Penny Nom lui répond. 





The diagonals of a hexagon 
20050815 

Brittany pose la question : are all of diagonals in a hexagon has same length Penny Nom lui répond. 





Jim is travelling from Toronto to Ottawa 
20050815 

Eleanor pose la question : Hi! I am looking for an easy way to solve this type of question: Jim is travelling from Toronto to Ottawa, a distance of 435 miles. He travels part of the way at a speed of 100 km/h and because of an accident, he uses a secondary road and travels at 70 km/h. If the trip took him 6.5 hours, how far did he travel on each of the two roads. Penny Nom lui répond. 





Is 360 Really the correct value? 
20050815 

Jack pose la question : Considering the circumference of a "Perfect Circle" with a Diameter of 1 meter would be something like 3.14 meters, why do we use the number 360 to represent the number of degrees within that circumference?
Would it not make more sense to express the degrees in reference to the relationship to the diameter as related to pi?
That is, let's just say our "Perfect Circle" has a circumference of 3.14 meters, therefore, what we now consider as due east would change from 90 Degrees to 78.5 Degrees. Penny Nom lui répond. 





Stock in a printing company 
20050812 

Tracy pose la question : Sam and Mary each owned onehalf stock in a printing company. Sam sold 2/3 of his stock to Mary. What fractional part of the printing business does Mary now own? Penny Nom lui répond. 





Framing an arched wall 
20050812 

Mike pose la question : I'm framing a building wall with a curved (arcing) top section. The radius of the section is 74'6" with a height above finish floor of 16'0". The horizontal run of the arced section is 23' 1 1/2" with a low height above finish floor of 12'4". If I start with a 16' stud at the high end how long are the subsequent studs if they are on 16" centers? Short of laying this out on a tennis court how can I work out the lengths of the studs? Penny Nom lui répond. 





A triangular lot 
20050810 

Elizabeth pose la question : If a piece of property was 100 ft on the west, 133 ft on the east and 100 on the north, how many acres is this or what fraction of an acre is this property? Penny Nom lui répond. 





The Maclaurin series generated by f(x)=x^ cosx + 1 
20050810 

Latto pose la question : f(x)=x^{3}·cosx + 1. but when I take the derivatives, I couldn't see a pattern. Can you help?
Penny Nom lui répond. 





Proof by induction? 
20050810 

Peter pose la question :
I am a lecturer and am having a problem with the following Proof by
Induction.
If
(N x N x N x N) + (4 x N x N x N) + (3 x N x N) + (N) = 4000
Prove that N is even!
Chris Fisher and Penny Nom lui répond. 





The volume of soil needed to fill a planter 
20050810 

Phil pose la question : I need to calculate the volume of soil needed to fill a planter box that measures  880mm W x 6080mm L x 900mm D. Penny Nom lui répond. 





Cubic feet 
20050810 

Selene pose la question : This is my math question I need to convert these inches to cubic feet
34"W x 34"H x 34"L Penny Nom lui répond. 





The number of four digit combinations 
20050809 

Kevin pose la question : My 12 year old has asked me how to figure out the number of four digit combinations possible using 0 thru 9 without repeating a number? Penny lui répond. 





how do i round up 9.6 to the nears ones 
20050809 

Carlos pose la question : how do i round up 9.6 to the nears ones Penny Nom lui répond. 





A two digit number 
20050809 

Grace pose la question : I am a 2 digit number. Both of my digits are even. My tens digit is 8 more than my ones digit. What number am I? Penny Nom lui répond. 





Constructing a fence 
20050809 

Andres pose la question : I was constructing my fence and was having some problems trying to do a perfect (or as close as possible) arch. If i know a section of a fence is for example 85 inches wide and I want a 4 inch rise from the top rail how do i figure out the radius? Penny Nom lui répond. 





At what rate is the circumference of the circle increasing? 
20050808 

John pose la question :
A mathematics professor is knitting a sweater. The main part of the sweater is knit in a large spiral, ending up with a diameter of 30 inches. She knits at a constant rate of 6/7 square inches per minute.
1. At what rate is the circumference of the circle increasing when the diameter is 2 inches?
2. How long will it take her to finish this piece of the sweater?
Penny Nom lui répond. 





A normal distribution problem 
20050808 

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. 





Area of a lot 
20050807 

John pose la question : We hope this copy of our survey map will help you to determine the acreage of our land. Harley Weston lui répond. 





Converting rational numbers 
20050807 

Joe pose la question :
I am helping my son with his converting rational
numbers in the form of A/B where A and B are integers and
B not equal to zero
I think I am doing this right but I am not sure so
below are the problems and our answers are beside
them, please let me know if these answerers are correct
Penny Nom lui répond. 





A golf outing for 16 golfers 
20050805 

Bob pose la question : I have a golf outing fast approaching and I’m having a problem matching the golfers so that everyone plays a round of golf with every other golfer in the group.
My problem is this: I have 16 golfers playing 5 rounds of golf. I would like a different foursome for every round of golf, that is each round (5 total) an individual is playing with 3 other players he hasn’t played with as of yet. Can you crunch the numbers and get back to me?
The way I see it, we have 20 combinations (5 rounds x 4 golfers) with numbers 1 thru 16. Chris Fisher lui répond. 





What is the radius of this planet 
20050805 

Kelly pose la question : Assuming that a NorthSouth line has been established, you set up two camps that are 67 miles apart. You now set up poles at each camp perpendicular to the ground. On a certain day at "noon" the pole at the South camp casts no shadow, while at the North camp a shadow is cast. The shadow makes an angle of 89 degrees with the horizontal. What is the radius, diameter, and circumference of this planet? Chris Fisher lui répond. 





Cubic yards of sand 
20050804 

Beth pose la question : I am trying to figure out how much sand I will need for ground cover under my children's playset. The area to cover is 30' x 30' and I want 4 inches of sand. Penny Nom lui répond. 





0.02 acres 
20050731 

Negin pose la question : know how much is 0.02 acres in square footage? Penny Nom lui répond. 





A perfect square that is equal to 1 acre 
20050731 

Shannon pose la question : If you have a perfect square that is equal to 1 acre, what is the length of the sides and how do you do it? Penny Nom lui répond. 





A television antenna sits on a roof. 
20050730 

Liz pose la question : A television antenna sits on a roof. Two 76foot guy wires are positioned on opposite sides of the antenna. The angle of elevation each makes with the ground is 24 degrees. How far apart are the ends of the two guys wires? Penny Nom lui répond. 





A concrete slab 
20050729 

Armand pose la question : I am
planning to pour a concrete slab over an existing slab in my garage
which is very uneven, with a depth variation from 2 1/2 inches to 5 1/2
inches from level. I'm afraid to over estimate concrete since it will be
wasted but worse, I'm afraid to underestimate. I've broken the slab down
into four sections with the following being the four dimensions, can you
tell me how much concrete I will need please, I would very much
appreciate your help.
1 6ft/8in x 20ft x 4 1/2 in. thick
2 16ft/10in. x 20ft x 3 1/2 in. thick
3 6ft/6in. x 16in. x 5 1/2 in. thick
4 6ft/6in. x 8ft. x 4in. thick
Penny Nom lui répond. 





Speed on a bicycle 
20050727 

Deborah pose la question : We are trying to figure out how many miles per hour we rode in a bike race. If the distance was l5 miles and the time it took was was 55 minutes, what is the speed? Penny Nom lui répond. 





Cubic feet in a mobile home 
20050722 

Jeanne pose la question : my mobile home is 24 x 56. I'm trying to find out how many cubic feet this is. I'm going to set of some bug bombs and it says 1 can will cover 4000 cubic feet. I don't know how to figure my cubic feet. the ceilings are 8 ft high everywhere but the living and dining room. They are vaulted and approximately 10 feet at the peak. I just need an estimate. Penny Nom lui répond. 





Some geometry problems 
20050722 

Sherry pose la question : 1. If Circle K has tangents RT and TY where R and Y are the points of tangency, then angle RKY and angle RTY are supplementary.
2. If one diagonal bisects a pair of opposite angles in a quadrilateral, then the quadrilateral is a kite. Penny Nom lui répond. 





A set of numbers whose sum is 1 
20050721 

Santos pose la question : Does there exist a set of numbers whose sum is 1, and the sum of whose squares is less than 0,01? Paul Betts lui répond. 





The period of sin(x) + cos(x) 
20050721 

A student pose la question : WHAT IS THE PERIOD OF SIN(X)+COS(X)? Penny Nom lui répond. 





Solve for x 
20050720 

Ed pose la question : ^{(x1)}/_{3}  1 = ^{(x + 2)}/_{2} Penny lui répond. 





How many tiles do I need? 
20050720 

Jeannette pose la question : I am putting up backsplash tile in my kitchen and I need to know how many tiles I would need to use for about 45 square feet using 4x4 tiles. Penny Nom lui répond. 





Three prime numbers p,q and r, all greater than 3, form an arithmetic progression: 
20050718 

Ladis pose la question : Three prime numbers p,q and r, all greater than 3, form an arithmetic progression: p=p, q=p+d and r= p+2d. Prove that d is divisible by 6. Chris Fisher lui répond. 





The equation of an ellipse 
20050717 

Allan pose la question : I working on a problem that asks me to give the equation of an ellipse when only the location of the directrix and the length of the latus rectum are given. No other points on the ellipse are given. Again, the only "givens" are:
Length of latus rectum = 12
Location of directrix is x = 16
If I could determine the eccentricity, I could proceed from there by taking the ratio of the distance from a focus to the latus rectum point to the distance of the point from the directrix, but I lack the x coordinate of c. I've searched the text, and feel I've "missed something" somewhere! I note that the latus rectum segment is unique in one respect in that it is parallel to the directrix, where any other line segment on the ellipse to the focus would not be. Please indicate where I'm going wrong. Chris Fisher lui répond. 





The area of a lot 
20050717 

John pose la question : A plot of land has the following dimensions: 391 ft. x 757 ft. x 208 ft. x 788 ft. Q: How many acres is this? Harley Weston lui répond. 





10% of $50 
20050716 

A student pose la question : If I had $50 and 10% of it had to go to my mother, how much would I have left? Penny Nom lui répond. 





A percentage of the whole 
20050716 

A student pose la question : two people both own property and would like to combine their properties into one. the first person contributes 1 acre and the second person contributes 1.5 acres. of the whole, how much percent does the first person own? Penny Nom lui répond. 





A lighthouse is located on a small island,... 
20050714 

Brittnee pose la question : A lighthouse is located on a small island, 3 km away from the nearest point P on a straight shoreline, and its light makes four revolutions per minute. How fast is the beam of light moving along the shoreline when it is 1 km from P? Penny Nom lui répond. 





Cubic yards of topsoil 
20050712 

Maggie pose la question : How much topsoil in cubic yards i need to order to cover 7500sq. ft. 3 inches deep? Penny Nom lui répond. 





The value of n*tan*(180/n) tends to pi 
20050711 

Daniel pose la question : I am 14 and i have been given a piece of maths coursework whereby a farmer has to fence off a piece of land as large as possible using 1000m of fence. I already know that the formula for working out the area of any shape of a 1000m perimeter = 500^{2}/ n*tan*(180/n), however, after some research I have found out that as the number of sides (n), tends to infinity, the n*tan*(180/n) tends to pi. Why is this? Penny Nom lui répond. 





A melting ice sphere 
20050709 

A student pose la question : A 2 meter diameter sphere of ice melts at 1.5 millimeters per minute. How many minutes will it take to fill up a hexagonal container measuring 1.5 meters on a side, and 0.8 meters deep? Penny Nom lui répond. 





The volume of a pool 
20050709 

Douglas pose la question : I have a pond that I need to treat with an anti algae solution which needs to applied based on the volume of water in the pond (in gallons).
The rough diameter of the surface of the pond = 25 ft
The depth of the pond = 8 ft
The pond shape is conical
How many gallons of water are in my pond? Penny Nom lui répond. 





What percent of 100,000 is 629.77? 
20050708 

Someone pose la question : What percent of 100,000 is 629.77? Penny Nom lui répond. 





Percent change 
20050701 

Betty pose la question : Can you tell me the difference between Percentage Change, Percentage Increase, Percentage Difference and please give an example of each, I am very visual. Penny Nom lui répond. 





The substitution method 
20050628 

Addie pose la question : how do i know where to began the substitution method? how do i solve
y = x + 1
2x  y = 1 Penny Nom lui répond. 





Seven digit numbers 
20050623 

Ky pose la question : How many number combinations are possible for a 7digit number? How many people in a population can exist without having to exceed the seven digit combinations and having to revert to a 8 or 9 digit number? Penny Nom lui répond. 





Profit of more than 100% of cost 
20050622 

sam pose la question : I know I can work out what percentage profit I am making by : profit/cost x 100, and I can work out up to 99% profit (the way I currently calculate it is profit x 1.99) But how do I work out any amount over 100%, say for instance I have something that costs me $0.52 that I wish to sell for 250% profit? Penny Nom lui répond. 





An algebraic remainder 
20050622 

Raymond pose la question : Given that 4x^{3}  kx is divisible by 2x+1, find the remainder when the expression is divided by 4  x^{2}. Penny Nom lui répond. 





A geometric sequence 
20050621 

A student pose la question :
The first three terms of a geometric series are 3(q+5), 3(q+3), (q+7) respectively.
Calulate the value of q. Penny Nom lui répond. 





Discriminant 
20050620 

A student pose la question : If a quadratic has real root, its discriminant b24ac>=0 Is there any similar condition or method by which you can find whether roots of a cubic equation are real or not? Chris Fisher lui répond. 





An octagonal gazebo 
20050619 

Tucker pose la question : I want to build a gazebo that is a regular octagon 15 feet across. How do I figure the length of each side? Harley Weston lui répond. 





An integer x when divided by 5 leaves the remainder 3. 
20050618 

A teacher pose la question : An integer x when divided by 5 leaves the remainder 3. Prove that when 4x is divided by 5, 2 is the remainder Penny Nom lui répond. 





Two tangents to a circle 
20050618 

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. 





p+1, p+2 y p+4 are prime 
20050618 

Vincent pose la question : Find all the values of p (where p is a natural number), for which the numbers p+1, p+2 y p+4 are prime. Penny Nom lui répond. 





In how many ways can 12 different fruits be distributed 
20050613 

Sapta pose la question : In how many ways can 12 different fruits be distributed among 3 boys so that each receives at least 1 fruit? Claude Tardif lui répond. 





20% profit 
20050612 

Shawn pose la question : If I know that I will be paid, say, $150.00, for labor, and I want to make
20% profit on what I pay for the labor, what is the calculation and factoring
process?
I see it like this
(x*.2)+x = 150
but I don't know how to factor it out from there. Penny Nom lui répond. 





The sum of the digits of 2^100 
20050611 

Richard pose la question : The sum of the digits was calculated for the number 2100, then the sum of the digits was calculated for the resulting number and so on, until a single digit is left. Penny Nom lui répond. 





The size of a lot 
20050609 

Bob pose la question : Is it possible to determine the square footage and acreage of a residential lot that's straight on 3 sides, and triangular on the 4th side?
As shown in the crude sketch below, the two legs of the triangle at the back end of the lot are 61' and 62'. Penny lui répond. 





Digging a hole for a pool 
20050608 

Debra pose la question : I need to have dirt hauled away from my built in pool and the haulers are asking me how many yards of dirt there is. How would I figure that out? It is a 24 ft round pool and 3 inches of soil depth was dug out. Penny lui répond. 





An octagonal deck 
20050607 

Scott pose la question : I want to build a octagonal deck. The wood I am using are cut in 8 foot lenghts. What I want to know is if the sides of the octagonal are 8 feet, what is the diameter. Also what are the angles of each side? Penny Nom lui répond. 





How many digits? 
20050607 

Floren pose la question : The numbers 2^{1989} and 5^{1989} are written one after another. How many digits in all are there? Claude Tardif lui répond. 





Asymptotes 
20050606 

Abraham pose la question : What are the equations of all horizontal and vertical asymptotes for the curve y=x/(x(x24))(the answer is y=0, x=2, x=2, but I want to know how to get that algebraically.And why isn't x=0 another asymptote?) Leeanne Boehm lui répond. 





The length of a whale 
20050604 

Judy pose la question : A whale's head is 72 inches long... its tail is as long as its head plus half the length of its body, and its body is half the entire length. Who long is the whale? Penny Nom lui répond. 





Primes 
20050604 

Fede pose la question : Prove that there is not a number prime p, for which the numbers p+5 and p+10 are prime too. Penny Nom lui répond. 





arccos(5/13) 
20050531 

Kyle pose la question : I would like to know how to evaluate the problem of: Arccos 5/13. Penny Nom lui répond. 





The numbers p and 8p^2 +1 are prime. 
20050530 

Antonio pose la question : The numbers p and 8p^{2} +1 are prime. Prove that the number 8p^{2}+2p+1 is also a prime number. Claude Tardif and Penny Nom lui répond. 





The volume of a sphere. Why 4/3? 
20050530 

Lauren pose la question : You know when you find the volume of sphere? I know the formula is V= 4/3 pi r^{3} but why do they use 4/3? Penny Nom lui répond. 





Square feet and cubic feet 
20050530 

Kim pose la question : Is there a relationship between square feet and cubic feet? Penny Nom lui répond. 





5+5+5=550 
20050530 

Bill pose la question :
5+5+5=550
This is a math equation that is not true.
How can it be made to be true by using only one line? Leeanne Boehm lui répond. 





Which is larger, 31^11 or 17^14? 
20050529 

Linda pose la question : Which number is greater 31^{11} or 17^{14} (without using
calculator). Chris Fisher and Paul Betts lui répond. 





The volume of a hopper 
20050528 

Brian pose la question : I would like to know the volume of this rectangular hopper. can you help Penny Nom lui répond. 





Cost price 
20050525 

Sunitha pose la question : What is (how to calculate) the cost price of a product which is markedup by 15% and retailed at $25? Penny Nom lui répond. 





A parabolic mirror 
20050524 

Nathan pose la question : i am trying to find the equation for a mirror for a laser experiment. the mirror is parabolic but my question is how do you find the equation when you know only the focus and the diameter the mirror diameter is 520 mm and the focus is at 1024 mm. would you just use the measurements in the equation instead of "nice numbers" or what. Penny Nom lui répond. 





Logarithmic differentiation 
20050523 

Richard pose la question : I need to convince myself that I understand the process of
differentiating y=x^{x}.
The specific question is that if I have to take the logarithm of both sides
of the equation how can differentiate the following?
y= {(x+2)^{(x+2)}}/{(x+1)^{(x+1)}}  {(x+1)^{(x+1)}}/(x^{x}),
I have an idea that the differential of this fairly complex function
is itself ... am I right or wrong. Penny Nom lui répond. 





Cubic feet of concrete 
20050523 

Robert pose la question :
REQUIRED CUBIC FEET OF CONCRETE TO POUR AN EXTENDED PAD
8 FEET X 8 FEET X 6 INCHES DEEP
Penny Nom lui répond. 





50^99 and 99! 
20050523 

Romel pose la question : Which number is greater, 50^{99} or 99! Claude Tardif lui répond. 





A triangular lot 
20050521 

Linda pose la question : I am looking to purchase a piece of property, and I need some help trying
to figure out the square footage of the land. I know that
normally if I multiply the length and width I could get my answer. However,
this piece of land is an odd shape and has 3 measurements. Can you
please help me.
The measurements for this piece of land is:
97.8'
201.2'
139.7' Penny Nom lui répond. 





The area of an octagon 
20050521 

Jeremy pose la question : i need to find the area of an octagon with each side measuring 1 foot Penny Nom lui répond. 





Factoring 
20050520 

Abraham pose la question : Can you please explain to me how to factor completely the following problem:
(sqrt(x+1))((x^{2}+2x+1)^{( 7/4)}). Penny Nom lui répond. 





A right triangle 
20050518 

Bill pose la question : If I know the base and the slanted side of a right triangle, how do I figure out the height? Penny Nom lui répond. 





The units digit 
20050518 

Gerald pose la question : Juan wrote the first 12 powers of 2. He noticed a pattern in the digits in the units places of the results. He said he could use this pattern to predict the digits for 2 to the power of 100. Penny Nom lui répond. 





The circumference of an oval pool 
20050518 

John pose la question : I have an oval pool of which I am trying to find the circumference. it is 38 feet long and 19 feet wide Penny Nom lui répond. 





Which is smaller 2^175 or 5^75? 
20050518 

Sarah pose la question : Which is smaller 2^{175} or 5^{75}? without using a calculator. Claude Tardif lui répond. 





A six digit answer 
20050518 

Angela pose la question : I have a 6 digit answer that is comprised of only 4 symbols: a square, a circle, a triangle, and an X. How many possible solutions are there and how is the best way to find out what ALL the solutions are? Penny Nom lui répond. 





Jobs relating to the topics of ratios and proportions 
20050517 

Alexa pose la question : What are some jobs relating to the topics of ratios and proportions other than architects and map makers? Walter Whiteley lui répond. 





Divisibility of a^2 + b^2 
20050516 

Ampa pose la question : given natural numbers a and b such that a^{2}+b^{2} is divisible by 21, prove that the same sum of squares is also divisible by 441. Penny Nom lui répond. 





What is my acreage? 
20050516 

Vonis pose la question : My property is 65.5 feet by 130 feet. what is my acreage? Penny Nom lui répond. 





L'hopital's rule 
20050515 

Abraham pose la question : Find the limit of [(1/(x+4))(1/4)]/x as x approaches zero.
How do you use l"hopital's rule to find this limit. I know how to do it with multiplying everything by 4(x+4), and getting the answer, 1/16.But how do you apply derivatives with l'hopitals rule to this type of problem? Penny lui répond. 





Angle of incline 
20050515 

Kyle pose la question : What is the degree of incline of a 12 foot plank that goes from 10.5 inches on one end to zero inches on the other? Penny Nom lui répond. 





How many cubic feet in a yard? 
20050513 

Carol pose la question : How do you measure a cubic foot? How many cubic feet in a yard? Penny Nom lui répond. 





Maximizing revenue 
20050513 

Jackie pose la question : 1.The manager of a 100unit apartment complex knows from experience that all units will be occupied if the rent is $400 per month. A market survey suggests that, on the average, one additional unit will remain vacant for each $5 increase in rent. What rent should the manager charge to maximize revenue?
2.During the summer months Terry makes and sells necklaces on the beach. Last summer he sold the necklaces for $10 each and his sales averaged 20 per day. When he increased the price by $1, he found that he lost two sales per day.
a. Find the demand function, assuming it is linear.
b. If the material for each necklace costs Terry $6, what should the selling price be to maximize his profit?
Penny Nom lui répond. 





Adding consecutive integers 
20050513 

Yas pose la question : i need some help with my work which is to investigating sums of consecutive numbers for example: 15= 4+5+6 and 15=1+2+3+4+5 Penny Nom lui répond. 





Surface areas 
20050511 

Jessica pose la question : How can I demonstrate to my high school students the reason for the formulas for the surface area of a prism, right cylinder, and regular pyramid, and right cone? Penny Nom lui répond. 





sin x + sin 2x + sin 3x + sin 4x = 0 
20050510 

Elia pose la question : I tried many times, but can't get to solve the following question:
sin x + sin 2x + sin 3x + sin 4x = 0 Chris Fisher lui répond. 





Some triangle problems 
20050506 

A student pose la question : 1.use the
heron's formula to find area of triangle ABC to nerest tenth
A.a=21 b=28 c=11
B.a=23 b=28 c=12
2.Find the nearest tenth the altitude of the longest side if a=3 b=3 c=5
3.the length of each side of a rhombus is 10 cm the length of one diagonal
is 12 cm find the area to the nearest square centermeter Penny Nom lui répond. 





y = x+2 and y = 2x  1 
20050503 

Kimberley pose la question : Question:
y=x+2
y=2x1 Penny Nom lui répond. 





16x^2+20x12x15 
20050503 

Tanya pose la question : how they got (4x+5)(4x5) from
16x^{2}+20x12x15=4x(4x+5)3(4x+5)=(4x+5)(4x5) Penny Nom lui répond. 





Graphing an inequality 
20050502 

Janice pose la question : I need to know how to graph inequalities. I need to know just abot everything. From graphing an equation to shading. Leeanne Boehm lui répond. 





Two problems 
20050429 

Sara pose la question :
#1 A boat is traveling in a straight line across a river from point D, directly opposite town P, to a point Q, two thirds of the distance from town P to town R. Towns P and R are towns on the same side of the lake and are 18 miles apart. Line DQ passes through town S, which is 8 miles north of town R. Points P, Q, and R are collinear. What is the length of QS in Miles?
How many miles does the boat travel across the river?
#2 What is the area of a regular hexagon if the perimeter is 24cm?
Penny Nom lui répond. 





Volume and surface area of a prism 
20050429 

Melissa pose la question : Can you please tell me if the volume and surface area of a prism can ever be the same? Could you please explain why or why not. Walter Whiteley lui répond. 





Area of a region on a map 
20050428 

Balachandar pose la question : Pl. find the attached map.
1. Can u pl. find out the total square are of WLMZ
2. Can u pl .find out the total square are of WXYZ  { A }
3. Can u pl .find out the total square are of XLMY  { B }
Pl .help me to find out the above.
..... Chris Fisher and Penny Nom lui répond. 





A quadratic equation 
20050427 

Chris pose la question : Solve using the quadratic formula
9x² + 9x  5 = 0
I don't get the same answer as in the text book which is
3+/ ^{√29}/_{36}
Hope you can help....
Penny Nom lui répond. 





A 5% increase 
20050427 

Debra pose la question : How can I determine the increased percentage of a dollar amount? I.e.: One dollar amount is $202 and another is $150, how can I determine the 5% increase from last year on the $202 dollar amount? Claude Tardif lui répond. 





Cubic yards of sand 
20050427 

Renee pose la question : I need to find out how much sand I would need to order for the base of a horse round pen. The pen is 40 ft across and I would like a depth of 4 inches. I have to order the sand in cubic yards. Penny Nom lui répond. 





Probability and smoking 
20050424 

Sean pose la question : 20% of a certain population smoke. For smokers the probability of dieing of lung cancer is ten times what it is for nonsmokers. Over all the probability of dying of lung cancer is .006. Find the probability for smokers and nonsmokers. Chris Fisher lui répond. 





A pyramid 
20050424 

Marc pose la question : I'm helping my daughter build a pyramid,it needs to be 30cm in height. I have cut out four pieces at 30 deg angles. When I went to join up the pieces it did not fit. I recheck my measuments and found that they were correct. Do I need to cut two pieces smaller so they can match up? Did I cut them at the wrong angles. My base is also 30cm, is that my problem? Chris Fisher and Harley Weston lui répond. 





An isosceles triangle...with 
20050423 

Shannon pose la question : If given an isosceles triangle...with
Is there any possible way to do this, without knowing a side, if so, please
explain in detail. Chris Fisher lui répond. 





A pattern of numbers 
20050421 

Claire pose la question : We need to be able to discover the nth term in a pattern of numbers and
explain how we did it. We have arrived at the formula 1+2+3+...n=n(n+1)/2
for trios where a trio series is;
3 has the following trio (1,1,1)
4 has the following trios (2,1,1), (1,2,1), (1,1,2)
5 has the following trios (3,1,1), (1,3,1) (1,1,3) (1,2,2) (2,2,1) (2,1,2)
So the series is as follows Penny Nom lui répond. 





The least integer of a set of consecutive integers 
20050419 

Lucia pose la question : The least integer of a set of consecutive integers is 25. If the sum of these integers is 26, how many integers are in the set? Penny Nom lui répond. 





40% profit 
20050419 

Carol pose la question : Could you please tell me the formula to calculate for example a 25% profit on cost.
I.e a sandwich cost .75p for the cost of ingredients, I wish to make a 40% profit on that cost so what do I multiply and divide it by to arrive at the selling price in order to achieve a 40% profit? Penny Nom lui répond. 





Percentage increase 
20050419 

Tom pose la question : What is the percentage increase from (negative $9262.00) to (positive $3840.00)? Penny Nom lui répond. 





Centimeters, millimeters and milliliters 
20050419 

A student pose la question : How many milliliters in a centimeter? Penny Nom lui répond. 





A Taylor series for ln(x) 
20050416 

Anood pose la question : i have to represent ln(x) as a power series about 2
i`m not getting the final answer which is ln 2+ sigma (((1)^{(n+1)}/
(n*2^{n}))*(x2)^{n}). i don`t get the ln 2 part
i show you my trial
f(x)= ln x.
f(x)=(1/x) .
f(x)= (1/x^{2})*1/2!
f(x)= (2/x^{3})*1/3!
f(x)= (6/x^{4})* 1/4!
so the pattern shows me that f(n)= ((1)^{(n+1)})/x^{n} *n)
so f(2)= sigma ((1)^{(n+1)})/2^{n} *n) *(x2)^{n}
so as you see i don`t get ln 2
Penny Nom lui répond. 





How much sand is in a pile? 
20050416 

Larry pose la question : I was wondering if there is a formula for determining how much sand would be in a pile. I am a student in medical school, and this is a bonus question for a test. I hope you can help me. Harley Weston lui répond. 





Some four digit numbers 
20050416 

Lori pose la question : can u give me every possible combination of four numbers starting with the number three Penny Nom lui répond. 





A roll of paper 
20050416 

Tuomas pose la question : How would you calculate a diameter of a paper reel when the paper is 0,04 millimeters thick and for example 5000 meters of it is winded on a 76 mm (3inch) core. Penny Nom lui répond. 





A flaw in a problem 
20050415 

Bryce pose la question :
Question:
(x^{2}x^{2}) = (x^{2}x^{2})
x(xx) = (x+x)(xx) [divide both sides by (xx)]
x = x + x
x = 2x [divide both sides by x]
2 = x/x = 1
Where is the flaw in this problem?
Paul Betts lui répond. 





X and Y intercepts 
20050414 

David pose la question : Hi, i would like to know if you can answer this question for me
Find the x and y intercept fo y = 8x  5 Penny lui répond. 





The limit as x approaches 3 of (sqrt(x+1)2)/(x3) 
20050414 

Abraham pose la question : What is the limit as x approaches 3 of
(sqrt(x+1)2)/(x3) Penny lui répond. 





cos(2x) = sin(3x) 
20050414 

A student pose la question : Show that if x= 18 degrees, then cos2x =sin 3x. HENCE find the exact value of sin 18 degrees, and prove that cos 36  sin 18 =1/2. Andrei Volodin, Claude Tardif and Penny Nom lui répond. 





Prime numbers 
20050411 

Jesule pose la question : Given that p, p+10 and p+14 are prime numbers, find p. Claude Tardif and Chris Fisher lui répond. 





A 25% markup 
20050407 

Jason pose la question : I want to markup $2.00 by 25%...How do I do this??? Penny lui répond. 





The centroid of a triangle 
20050407 

Maria pose la question : Q3)find the coordinates of the centroid of triangle ABC
i want your help here to solve the 3rd question i got stuck. Penny Nom lui répond. 





A mixture 
20050406 

Ray pose la question : two known values
product # 1 = 60% protein
product # 2 = 80% protein
How much of the #2 product would I need to add to the # 1 product to
create a third product of 65%
Penny lui répond. 





Difference in latitude 
20050405 

Gretel pose la question : Assuming the the earth is a sphere of radius 6378 kilometers, what is the difference in latitude of two cities, one of which is 400 kilometers due north of the other? 500 kilometers? Penny Nom lui répond. 





Rational functions 
20050405 

Nicole pose la question : My name is Nicole and I am a teacher at Weyburn Comprehensive School. I am currently teaching both Math B30 and Calculus 30 at the school and I have a question about rational functions. I know that if a rational function (by definition) has common factors in the numerator and the denominator then it is not a rational function (math b30) however in calculus this common factor creates a hole in our graph. Can you explain to me why a common factor or constant does not give us a rational function? Penny Nom and Leeanne Boehm lui répond. 





A matrix problem 
20050404 

Alan pose la question :
Let A = 

1  1  0 

2  1  2 
a  b  c 
where a, b, c are constant real numbers. For what values of a, b, c is A invertible? [Hint: Your answer should be an equation in a, b, c which satisfied if and only if A is invertible.]
Judi McDonald lui répond. 





Ax + By = C 
20050403 

Farzana pose la question : I was wondering if you could please explain to me how I would write the equation of line through the given points [(3,7), (0,5)] in Ax+By=C form. Penny Nom lui répond. 





Some liquid in a cone 
20050403 

Vasuki pose la question : There are 2 right cones, height is X. one of them is filled from the bottom up (round side) = x/2, when you invert the cone and add the same amount of liquid inside the second cone, what is the HEIGHT of the liquid? Penny Nom lui répond. 





Bayes Theorem 
20050403 

wei pose la question :
In the January 11,1988,issue of the Oil&Gas Journal, R.A.Baker
describes how the Bayesian approach can be used to revise probabilities
that a prospect field will produce oil. In one case he describes,
geological assessment indicates a 25% chance the field will produce
oil. Further,there is an 80% chance that a particular well will strike
oil given that oil is present on the prospect field.
 Suppose that one well is drilled on the field and
it comes up dry. What is the probability the prospect field will
produce oil?
 If two wells come up dry, what is the probability
the field will produce oil?
 The oil company would like to keep looking as long
as the chances of finding oil are greater than 1%. How many dry wells
must be drilled before the field will be abandoned
 If the first well produces oil,what is the chance
the field will produce oil?
Andrei Volodin and Penny Nom lui répond. 





Gallons in a tank 
20050402 

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. 





An asphalt driveway 
20050402 

Bob pose la question : I'm trying to convert square
feet to cubic yard.
I have an asphalt drive way I'd like to replace with concrete. Concrete
is sold by the cubic yard and I keep telling myself that their must be an easy
conversion table out there somewhere.
My driveway is 18 feet wide and 47 feet long with a proposed depth of 4
inches. Penny Nom lui répond. 





An inequality 
20050331 

Ambross pose la question : demostrate the following inequality:
2.Sqrt(K+1)2.Sqrt(k)<1/Sqrst(K)<2.Sqrt(K)2.Sqrt(k1)
Penny Nom lui répond. 





The integral of tan^4x 
20050331 

Nicole pose la question : college student. need help with tough integral.
the integral of 2tan^{4}xdx
Penny Nom lui répond. 





tan55.tan65.tan75=tan85 
20050330 

Jesus pose la question : My name is Jesus and I´m a secondary student. I´m trying to verify a trigonometric identity but I don´t know how to do it.please help me!!!!!!!!!.
The identity is : tan55º.tan65º.tan75º=tan85º (the sign (.) indicates multiplication)
Chris Fisher and Penny Nom lui répond. 





Two matrix problems 
20050330 

Sue pose la question : Question 1
Suppose all matrices in the equation below are square and invertible. Solve for x .
BA1XB1 + 2BA + In = 0 (the symbol "0" here denotes the matrix of all 0's in it)
Also, A1 or B1 is indicating inverse and "In" = for example, A1 times A
I hope you understand the above. I have to show all the steps.
Question 2
Suppose we consider the set of all 2x2 matrices along with the operations of matrix addition and multiplication. Do they form a field? Why or why not?
I think the answer is no because under multiplication it is not commutative and not all square matrices are invertible. I not positive so I'd like some help. Penny Nom lui répond. 





The shortest distance from a point to a line 
20050330 

carly pose la question : Find the shortest distance from the point (15, 2.5) to the line 5x+6y=30. Penny Nom lui répond. 





A wishing well 
20050328 

Don pose la question :
I am building a wishingwell
out of pieces of 2by4. I have included a picture of a miniature version
of what I want. There are to be ten 2by4 pieces around the well and
I want the circle around the outside of the structure to have a diameter
of approximately 3 feet. How long to I cut the 2by4's to build the
wishingwell.
Thanks,
Don
Harley Weston lui répond. 





Explain why 3(x+2) = 3x+2 is incorrect 
20050328 

Cynthia pose la question : An algebra student incorrectly used the distributive property and wrote 3(x+2) = 3x+2. How would you explain to him the correct result, without the use of the distributive law?
Explain why the square of the sum of two numbers is different from the sum of the squares of two numbers. Penny Nom lui répond. 





A product equals a sum 
20050327 

Tor pose la question : Can you please help me with a general formula for the following system:
2+2=2*2
3+3/2=3*3/2
4+4/3=4*4/3
and how will you prove the formula?
Penny Nom lui répond. 





A torus and a sphere 
20050327 

Tony pose la question : Is it possible to shrink a torus into a sphere? Andrei Volodin and Penny Nom lui répond. 





Gasoline in a cylindrical tank 
20050323 

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. 





Expanding (x+2)(x+3) 
20050323 

Rick pose la question : The problem involves writing expressions, one in factored form and one in expanded form, for the area of a rectangle of sides x+2 and x+3. We've gotten as far as area = (x+2)(x+3). But I can't come up with the other expression. Penny Nom lui répond. 





Find the height of the pole 
20050322 

Dorothy Jean pose la question : From the top of a building 70ft.high, the angle of elevation of the top of the pole is 11.2 degrees. From the bottom of the building the angle of elevation of the top of the pole is 33.4 degrees. Find the (a) height of the pole and (b) the distance from the building. Penny Nom lui répond. 





ax+b = cx + d 
20050322 

Angel pose la question :
ax+b = cx + d
how to show sometimes the above has 2 roots, sometimes 1 root and sometimes
no roots. Hopelessly lost on how to start...
Penny Nom lui répond. 





The answer to a subtraction problem 
20050322 

Libby pose la question : What is the name of a number that is the answer to a subtraction problem? Diane Hanson and Claude Tardif lui répond. 





Two overlapping circles 
20050320 

Safi pose la question : I have a problem to calculate the area of two overlapping circles because two circles are overlap then how i calculate the overlap area to subtract from the area of both circle. Penny Nom lui répond. 





Tangents to a circle 
20050319 

Sue pose la question :
You're given the equation to a circle (x3)^{2 }+ (y3)^{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. 





Dimensions of a roof 
20050318 

A roofer? pose la question : A right triangle (roof of a house) has a base of 7 feet and a 22 degree angle. What is the height of the roof and what is the hypothenus of the triangle. Penny Nom lui répond. 





The sum of the digits 
20050316 

kelsey pose la question : What is the sum of the digits in the decimal form of 2^{1999} * 5^{2002}? Claude Tardif lui répond. 





A matrix construction problem 
20050314 

Marcelo pose la question : I want to know if is it possible to solve this problem:
I have an empty NxM matrix and I know totals (sum) by rows and totals by column.
Is there any algorithm to fill the matrix so that the summary of columns and rows gives the original values I have? Harley Weston lui répond. 





If the mixture is 1 pint to 6 gal 
20050313 

Trey pose la question : If the mixture is 1 pint to 6 gal. Do i use 4 pints to 24 gallons of gas Penny lui répond. 





The volume of a stock tank 
20050313 

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. 





The square root of 2 
20050312 

Madhumita pose la question : From Pythagoras theorem we can draw square root 2 as a finite distance but it is irrational number which is endless. Explain how we can equate these two. Harley Weston lui répond. 





Doubling time 
20050312 

Nick pose la question : Looking for the equation to how many years it will take to double the population given the growth rate is 7%. Penny Nom lui répond. 





How many three digit numbers can I make from the four cards 
20050312 

Sue pose la question : I have four playing cards 2,3,4,5 of hearts. How many three digit numbers can I make from the four cards. Penny Nom lui répond. 





The benefits of saving for retirement 
20050311 

Nick pose la question : A human resources department wants a report that shows its employees the benefits of saving for retirement. Produce a report that shows 12 predicted retirement account values for each employee  the values if the employee saves 5, 10, or 15% of his or her annual salary for 10, 20, 30, or 40 years. Assume that savings grow at a rate of 8% per year. Not really interested in answers, just the equations to solve the problems. Penny Nom lui répond. 





The ratios of Business, Accounting and Engineering majors are: 7:8:10. 
20050311 

John pose la question : There are 500 students in a collage class. The ratios of Business, Accounting and Engineering majors are: 7:8:10.
How many Engineering majors are there in the class?
Penny Nom lui répond. 





21yd 2ft divided by 5=what? 
20050310 

A student pose la question : 1gallon 3qt divided by 6= what?
21yd 2ft divided by 5=what? Penny Nom lui répond. 





Discrimination based on gender? 
20050310 

A student pose la question : After being rejected for employment, Kim learns that the Bellevue office has hired only two women among the last 20 new employees. She also learns that the pool of applicants is very large, with an approximately equal number of qualified men and women. Help her address the charge of gender discrimination by finding he probability of getting two or few women when 20 people are hired, assuming that there is no discrimination based on gender. Does the resulting probability really support such a charge? Penny Nom lui répond. 





A wrestling schedule 
20050308 

Ed pose la question : Hello my name is Ed and I am a couch of a wrestling team in New Jersey. I was doing searches for formulas on how to make a matrix for team sports and it seems to be hard to find. I came some how to your site and thought I'll give it a try. Here is what we need or are trying. Claude Tardif lui répond. 





A nine week schedule 
20050308 

Greg pose la question : I'm trying to build a nine
week schedule where 10 teams play each other once throughout the season.
I make it all the way to week nine, then I start having all sorts of
conflicts.
HELP!!
Claude Tardif lui répond. 





Biodiesel 
20050308 

William pose la question : My son is doing an demonstration for science class about how to make biodiesel. we are having problems with the conversion. for instance we think there are approx 190 liters in 50 gallons. Is this correct? Also if you needed 3.5 grams of lye per liter, would that be 662g of lye. Penny Nom lui répond. 





The cost of concrete 
20050308 

Cathy pose la question : Compute the cost of ready mixed concrete for a driveway 70ft long, 10ft wide, 3 inches deep at a cost of $30.00 per cubic yard Penny lui répond. 





A diagonal in a cube 
20050306 

Brett pose la question : A cube has a volume of 64 cubic inches. What is the length of segment AB? Segment AB is a straight line from the top left corner of the cube to the lower right bottom corner Penny Nom lui répond. 





Perfecting an ideal gambling system 
20050306 

Gaz pose la question : I am a screenwriter, currently in the fortunate position of having the development of a Screenplay funded by the South Australian Film Corporation. The (anti)hero of this screenplay is a statistician whose life is falling apart around him, thanks in part to his obsession with perfecting an "ideal" gambling system. Andrei Volodin lui répond. 





A trig identity 
20050306 

Patrick pose la question : im trying to verify this
identity:
sin(x)+sin(5x)
 = tan(3x)
cos(x)+cos(5x)
Chris Fisher lui répond. 





I need to fill an area with rock 
20050304 

Kelly pose la question : if I need to fill an area with rock that is 64 feet long by 4 feet wide and 1 foot 2 inches in depth
how many tons of rock will this job require?
it is also sold by cubic yard how many of these cubic yards will I need? Penny Nom lui répond. 





Spraying roses 
20050303 

A student pose la question : A litre and a half of water has 0.045 grams of herbicide added for spraying roses. How many grams of herbicide per litre is this? Penny Nom lui répond. 





How much of a acre is this? 
20050302 

Ken pose la question : my property is 11,914 square ft. How much of a acre is this? Penny Nom lui répond. 





Reverse pecentage 
20050301 

Nathan pose la question : Question for you. If I have spent $10.00, what is the mathamatical equation to
figure out what the G.S.T (7%) was?
Also if I were to spend $80.00 on a hotel, and I would like to know how much
G.S.T (7%) and how much provincial tax (6%) I spent how would I go about this.
Penny Nom lui répond. 





The area of a quadrilateral 
20050227 

Jonathan pose la question : I want to know how to find the area of a quadrilateral. Penny Nom lui répond. 





A triangle question 
20050226 

John pose la question : H=10' 7and3/4",angleX=30 degrees solve for the adjacent side Penny Nom lui répond. 





A countably infinite collection of countably infinite sets 
20050226 

Feroz pose la question : Suppose a set can be divided into a countably infinite number of countably infinite sets.Then can the original set be considered as a countably infinite set? Penny Nom lui répond. 





A 3digit product 
20050225 

A student pose la question : I have an odd 3 digit product. My factors are a 1 digit number and either a 2 or 3 digit number. My factors are odd, but neither is 1. Find my factors and my product. Penny Nom lui répond. 





The volume of a sphere 
20050225 

Stephanie pose la question : find the volume of a sphere that has a diameter of 12 cm.
please show me how to work this problem Penny Nom lui répond. 





Trading fish for bread 
20050225 

Mike pose la question : Byron lives where people trade goods they produce for other things they
need. He has some fish and wants to trade them for bananas. He finds
the following:
5 fish = 2 loaves of bread
6 oranges = 2 melons
1 loaf of bread = 1 banana and 3 oranges
4 loaves of bread = 14 oranges
How many bananas can Byron get with 5 fish? Penny Nom lui répond. 





Cubic feet and feet 
20050225 

Nancy pose la question : How do you convert cubic
feet into feet?
The problem is to convert 90 cubic feet into feet. Penny Nom lui répond. 





The capacity of a dryer 
20050223 

Darlene pose la question : I am trying to figure out the capacity of my dryer. I need to know the size in order to buy a new one. The drum within measures 27" in diameter and 18" deep. I know that I am looking for an answer in cubic feet but am not sure how to determine this.
Penny Nom lui répond. 





An irregular pentagon 
20050223 

Tony pose la question : Please help me with confirming the area in square footage of the irregular pentagon
My Name is Tony and I am working on understanding the square footage as calculated in the drawing. I also believe this is a secondary level question.
I saw the example http://mathcentral.uregina.ca/QQ/database/QQ.09.03/dana2.html and would appreciate how you worked through the problem, but couldn't find the calculations so that I could adapt them to my sizes. Penny Nom lui répond. 





13 puissances 2005 
20050222 

Un eleve pose la question : je voulais vous demander combien fait 13^{2005}
(13 puissances 2005) svp Claude Tardif lui répond. 





Each interior angle of a particular polygon is an obtuse angle... 
20050222 

Victoria pose la question : Each interior angle of a particular polygon is an obtuse angle which is a whole number of degrees. What is the greatest number of sides the polygon could have? Walter Whiteley lui répond. 





Grams per liter 
20050220 

A student pose la question : A litre and a half of water has 0.045 grams of herbicide added for spraying roses. How many grams of herbicide per litre is this? Penny Nom lui répond. 





Factoring a cubic 
20050220 

Abraham pose la question : How would you factor completely,
x^{3}x^{2}+5x5? Claude Tardif lui répond. 





$14k is 22% of ________ 
20050219 

A parent pose la question : When one knows the
percentage, and a known number, how is the unknown total figured? In other
words, I know that $14k is 22% of what number?? Claude Tardif and Penny Nom lui répond. 





1 pied linéaire 
20050218 

Christiane pose la question : Pouvezvous m'indiquer 1 pied linéaire égale quoi? 3 pied....? Claude Tardif lui répond. 





Graphing inequalities 
20050215 

Melanie pose la question : Solve and Graph the following variable inequalities:
y<2x+4
y>2x+6
3x+4y<24
4x6y>24 Penny lui répond. 





The weight of some concrete 
20050215 

Jordan pose la question : I have 6 acres of concrete that is 3 feet thick the aprox. weight of 1 cubic yard of concrete is 4024 pounds I am trying to find out how much my 6 acres weighs. fortunately my concrete is 3 feet deep. Penny Nom lui répond. 





If the distance of a person from a tower is 100 m... 
20050215 

Agustin pose la question : If the distance of a person from a tower is 100 m and the angle subtended by the top of the tower with the ground is 30 degrees, what is the height of the tower in meters?
Harley Weston lui répond. 





One million times one billion 
20050215 

A student pose la question : How much is ONE MILLION TIMES ONE BILLION in the American system ? Penny Nom lui répond. 





What is the least threedigit palindrome that is a square number? 
20050212 

Ben pose la question : What is the least threedigit palindrome that is a square number? Chris Fisher and Penny Nom lui répond. 





Understanding fractions 
20050211 

C.J. pose la question : I have some questions about the lesson, "Understanding Fractions" by Diane Hanson, Regina Catholic Schools. How successful was the lesson? Are there any changes you would recommend? Diane Hanson lui répond. 





arcsech x 
20050210 

Monica pose la question : Prove that arcsech x = ln[(1 + (1x^{2})^{(1/2)}) / x ] Penny Nom lui répond. 





Th dimensions of a garden 
20050209 

Rebecca pose la question : Nate's garden has a perimeter of 34 meters and an area of 72 square meters. What are the dimensions of the garden? Penny Nom lui répond. 





Sales before tax 
20050209 

Lynda pose la question : I know my total sales for the month, which includes sales tax. How do I get to the sales dollars before the sales tax? Penny Nom lui répond. 





A quadratic equation 
20050209 

Jess pose la question : 6x+8=x2 Claude Tardif lui répond. 





A combination lock has 60 positions... 
20050207 

Kathy pose la question : A combination lock has 60 positions arranged in a circle to which a pointer may be set. Three settings are required to open it and no one setting may be closer than 5 positions from the immediately preceding setting. How many different locks may be manufactured? Penny Nom lui répond. 





Conversion of a recipe 
20050206 

Peg pose la question :
A Hungarian friend gave me an old, old family recipe and it calls for:
20 dg. sugar
15 dg. filbert
I can't find a conversion table anywhere that explains how to get ounces from "dg." Do you know what the equivalent would be in ounces of dry measurement?
Harley Weston lui répond. 





Extraneous solutions 
20050204 

Heather pose la question : My teacher wants to know why there are extraneous solutions in logarithms? Penny Nom lui répond. 





A seating arrangement 
20050203 

Kay pose la question : If you have 5 married couples, how many arrangements can be made if they must sit across from each other? Penny Nom lui répond. 





Three debts 
20050203 

Kat pose la question : If I have three debts and 49% percent of total debt is loaned at 9% intrest, 34% of the debt is at 21% intrest and 17% of the total debt is at 14% intrest, how do I calculate the average rate of intrest on total debt? Penny Nom lui répond. 





Strategies for teaching operations with positive and negative decimal numbers 
20050202 

Erin pose la question : I am wondering if you can suggest any strategies for teaching operations with positive and negative decimal numbers that do not rely on rules that must be memorized? Diane Hanson lui répond. 





The diaonals of an isosceles trapezoid are congruent 
20050202 

Daniel pose la question : I am currently unable to find a proof that the diaonals of an isosceles trapezoid are congruent. Might you happen to have one? Walter Whiteley lui répond. 





Solve for x 
20050202 

Christie pose la question : Solve for x
.387 = (.40  .265x)/(sqrt(1x2)) Penny Nom lui répond. 





A line segment connecting two vertices of a polygon 
20050202 

James pose la question : What is a line segment (not a side) connecting two vertices of a polygon called? Penny Nom lui répond. 





The volume of an aquarium 
20050201 

Selena pose la question : Im trying to figure out the amount of gallons from a rectangle 48x20x12? Penny Nom lui répond. 





'zero divided by one' and 'one divided by zero' 
20050131 

Katrina pose la question : Please advise how best to explain the distinction between the solution to 'zero divided by one' and 'one divided by zero'. I remember being told in school that one of them is undefined and the other is zero but I'm having difficulty with calculating and explaining it to some highly curious 10 year olds! Claude Tardif and Walter Whiteley lui répond. 





Are the vetices of this quadrilateral concyclic? 
20050130 

A student pose la question : Show that the peints A(2,0),B(6,6),C(1,7) and D(2,6) are concyclic. Also find its circum radius. Chris Fisher lui répond. 





Sum to n terms of the series i.(2^(ni)) 
20050128 

Satya pose la question : Sum to n terms of the series i.(2^{ni}) Penny Nom lui répond. 





Some logarithm problems 
20050127 

Jo pose la question : Given ln x=7.1; ln y=8.2, Find ln(x^3y^7) Penny Nom lui répond. 





By how much is 100 multiplied or divided,... 
20050127 

Benedict pose la question : By how much is 100 multiplied or divided, so that whether the number obtained is divided by 5 or 7, there will be a remainder of 1 and so that at the same time, the first quotient is greater by 4 than the second? Penny Nom lui répond. 





Approximating an integral 
20050127 

A student pose la question : i used excel to find the area under a graph instead of integrating the function the analytical way. These are the different answers i got with different width of the xvalues, the smaller the xincrement gets the more precise the area is when compared to the answer obtained the numerical way. I have trouble seeing why the answers i get is getting bigger and bigger and not smaller can someone plz explain? Penny Nom lui répond. 





A combination question 
20050126 

Kelly pose la question : A computer with an old processor locks up if more than 4 applications are running at the same time. If the owner has 20 applications stored in his program file, how many different sets of 4 can he run, so that his computer does not lock up? Penny Nom lui répond. 





un nombre entier 
20050125 

Un eleve pose la question : comment démontrer qu un nombre entier est un carré parfait si et seulement si il admet un nombre impair de diviseurs? Claude Tardif lui répond. 





Three tangent circles 
20050125 

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. 





Differentiating F(x,y) = 0 
20050123 

Jacob pose la question : In calculus, we often mention to the students that if F(x,y) = 0, then we can differentiate both sides and still get an equality. The problem is that we can't perform the same operation on F(x) = 0, say x = 0, otherwise 1 = 0, which is absurd. What is the reason? Walyer Whileley and Harley Weston lui répond. 





cos 2x = sin x 
20050122 

Kris pose la question : solve the equation
cos 2x = sin x for 0<= x < 360 Penny Nom lui répond. 





When dividing a 3digit number by a 1digit number... 
20050122 

A student pose la question : When dividing a 3digit number by a 1digit number, for what divisors can you get a remainder of 8? Penny Nom lui répond. 





The diameter of a 800 km circle 
20050122 

Mechelle pose la question : What is the diameter of a 800 km circle? Penny Nom lui répond. 





A 6 sided (hexagonal) pyramid 
20050122 

Steve pose la question : im trying to make a 6 sided (hexagon) pyramid, from 6 triangles of 12mm plywood, i know all the angles to cut apart from the one one to join all 6 triangles together. Rough measurements are outer edge (A) of each triangle is 13cm's, length of other 2 sides (B&C) of triangle outside to center is 14cm's with a height of the whole thing together about 6cm's. Chris Fisher and Harley Weston lui répond. 





The area of a triangle 
20050121 

Amy pose la question : In tirangle ABC, AB=6, BC=9, BC is the angle bisector of angle ABC and M is the midpoint of BD. If the area of ABC is 30, what is the area of ABM?
The height comes out greater than the hypotenuse, but the teacher said that there's an answer for it. Can you show me how? Thanks Chris Fisher lui répond. 





Finding the missing side of a triangle 
20050120 

Jason pose la question : I found a geometry problem that reads as follows:In triangle ABC, Penny Nom lui répond. 





The angle between two forces 
20050119 

Abraham pose la question : One force of 20 pounds and one force of 15 pounds act on a body at the same point so that the resultant force is 19 pounds. Find, to the nearest degree, the angle between the two original forces. Penny Nom lui répond. 





The radius of a circle 
20050118 

A student pose la question : find the radius of a circle whose area is 1256sq cm.Use pi as an appoximation for pi. Penny Nom lui répond. 





A nonrerctangular lot 
20050118 

EM pose la question : One corner of a 60X120 foot lot, otherwise rectangular, is a curve with a radius of 20 feet and a central angle of 90 degrees. What is the area? Penny Nom lui répond. 





The side of a cube 
20050117 

Jake pose la question : I have one for you that's got me stumped. Is it possible to calculate the dimensions of a square if I have the cubic feet? Say I know the package to be 180 cubic feet. Penny Nom lui répond. 





Stewart's Theorem 
20050117 

Amy pose la question : In triangle ABC, AB=4, AC=6 and AD=5, where D is the midpoint of BC. Determine BC. Chris Fisher lui répond. 





Numbers that John likes 
20050116 

Garrett pose la question : John likes 400 but not 300; he likes 100 but not 99; he likes 3600 but not 3700. Which does he like?
900
1000
1100
1200 Penny Nom lui répond. 





The area of a trapezoid 
20050115 

Doak pose la question : What is the total acreage of a pieshaped piece of land that is:
146' f ront
85' back
246' each side
The front and back lines are fairly straight....a trapezoidal shape. Penny Nom lui répond. 





The length of a chord 
20050113 

A parent pose la question : Does anyone have a formula for calculating the chord length for a segment of a circle when you know the radius and the enclosed angle or radian ? Penny Nom lui répond. 





The tide at a boat dock 
20050111 

Abraham pose la question : The tide at a boat dock can be modeled by the equation
y = 2cos(pi/6 t) + 8,
where t is the number of hours past noon and y is the height of the tide, in feet. For how many hours between t=0 and t=12 is the tide at least 7 feet? Penny Nom lui répond. 





The game of 24 
20050110 

Manny pose la question : HI  my daughter and I are being driven crazy by the following "24" question 7,7,3,3. She's good at the game (well, better than I am) and her teacher gave her this one. Any insight would be appreciated! Claude Tardif lui répond. 





Profit 
20050110 

Abraham pose la question : The profit a coat manufacturer makes each day is modeled by the equation P(x)=x2+120x2000, where P is the profit and x is the price for each coat sold.For what values of x does the company make a profit?
I don 't understand this problem(how to do it) and hope you can help me. Penny Nom lui répond. 





Arcs and chords 
20050109 

Aniesha pose la question : A chord of a circle is 48 centimeters long and is 10 centimeters from the center of the circle. Find the radius? Penny Nom lui répond. 





Acres 
20050108 

Jim pose la question : What size is this lot?
And is there a location on the web where you can plug in lot dimensions to figure acreage?
North = 180ft
South = 210ft
West = 336ft
East = 244 ft Harley Weston lui répond. 





ln(hx+n) 
20050107 

Anibal pose la question : if I have the eq.
y=hx+n
and I want to know ln(y), how do I process
ln(hx+n)? Penny Nom lui répond. 





Quadratics 
20050105 

Usman pose la question : Hi, in my Grade 11 Functions math class we have been assigned the task of finding jobs and careers related to quadratics, I have done many searches but have been unsuccessful, then I saw your website and emailed. I also have to use an example of a math problem that the job uses, then solve it, this will all compile on bristol board for a presentation. I would greatly appreciate it if you could send me some links and references of sources that refer to this subject. Harley Weston lui répond. 





There are 4 contestants in a bicycle race. 
20050105 

Robert pose la question : There are 4 contestants in a bicycle race. In how many different orders can they cross the finish line? Penny Nom lui répond. 





Express the answer in dollars 
20050103 

Abraham pose la question : My question on this question is if I wrote just 5280 because they say they want it in dollars, is that correct or is the only answer, 5279.61 as their answer key says? How should I have known to give it with cents? Should I give myself full credit? Harley Weston lui répond. 





An isosceles triangle 
20050103 

Abraham pose la question : The question is,"Triangle ABC is not isosceles.Prove that if altitude BD were drawn, it would not bisect AC."My question is If an altitude is drawn wouldn\'t that mean automatically its isosceles because, In a triangle the sides opposite congruent angles(in this case the right angles)are congruent? What am I thinking wrong? Harley Weston lui répond. 





A sequence of transformations 
20050103 

Abraham pose la question : Please go to this web site and look at number 31.
http://www.nysedregents.org/testing/mathre/matharch/mathbtestau02.pdf
That is the New York state education web site.
Can you tell me if my answer would be marked correct? My answer was Transformation of 4,3 (T 4,3) followed by a reflection in the xaxis.If I graphed the question and wrote that, would I get full credit Harley Weston lui répond. 





An elliptical table 
20050103 

Roger pose la question : Want to make an elliptical table, say the long (major) axis is 4 feet, and the short (minor) axis is 3 feet. I can construct this figure, but I'm trying to figure out what the exact dimension of a rectangle within this ellipse will be if I make the table a drop leaf type where the drop dimensions are equal for each end of both the long and short axes. Intuitively, it looks like there is one and only one solution. Penny Nom lui répond. 





Standard deviation 
20050102 

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. 





A 4digit access code 
20050102 

Missi pose la question : I need to find the 4 digit number to access my voice mail. These numbers will be 09 & numbers can be repeated. Could you provide me with a list of possibly combinations? If not, do you know anywhere that I could get a list of combinations so I don't have to write it all down? Harley Weston lui répond. 





A line from the center of the patch to the periphery 
20050101 

Sandrine pose la question : I am currently researching a patch disease of grasses. These patches are roughly circular. I need a term for a line from the center of the patch to the periphery. Since the patches are not perfectly circular, my supervisors tell me I cannot use the word 'radius'. What else could I use? Denis Hanson and Harley Weston lui répond. 





A geometry problem 
20050101 

Alexandra pose la question : In triangle ABC, b=40, and angle A= 30 degres. What values of BC will give two solution for angle B? Penny Nom lui répond. 





The golden ratio 
20041231 

Cristina pose la question : let x represent the longer segment. to find the golden ratio, write a proportion such that the longer of the two segments is the geometric mean between the shorter segment and the entire segment.Use the quadratic Formula to solve the proportion for X. Find the value in both radical and decimal form. Penny Nom lui répond. 





The area of a triangle 
20041230 

Perry pose la question : What is the area of a triangle with dimensions 3"X5"X7"? Could you provide the formula? Penny Nom lui répond. 





Gallons in a cylinder 
20041229 

Dean pose la question : I have 2 cylinders:
Cylinder A = 8'D x 12'H
Cylinder B = 10'D x 15'H
Each 1ft represents how many gallons of fluid?
Cylinder A=?
Cylinder B=? Penny Nom lui répond. 





Cubic yards of dirt 
20041228 

Stephen pose la question : How many cubic feet or yards of dirt would be required to cover a 5 acre tract of land to a depth of 10 feet of compacted dirt? Penny Nom lui répond. 





Six digit numbers with at least one 7 
20041227 

Behzad pose la question : How many sixdigit numbers contain at least one 7 in their decimal expansion? Penny Nom lui répond. 





2^9833 days from today 
20041226 

Pauline pose la question : Today is Monday, 1 October 2001. What day of the week will be 29833 days from today? Penny Nom lui répond. 





Half of five 
20041226 

Pauline pose la question : Why is four half of Five? Hint: It's the middle half? Penny Nom lui répond. 





Modelling monthly temperature with a cosine 
20041225 

Regis pose la question : The average monthly temperature for a location in Ontario as a function of month number can be modelled using the equation y = a cos[k(t + b)] + d. Harley Weston lui répond. 





An arithmetic progression 
20041224 

A student pose la question : the 4th and 5th term of an arithmetic progration 47 and 52 respactively find
a)d
b)a1
c)a50 Penny Nom lui répond. 





Irrigation and a sector of a circle 
20041223 

Chuck pose la question : A friend of mine is a farmer and uses Pivots to irrigate portions of his land. The crop rows are in straight lines that all form chords of a large circle. The intent is to determine area between any two "boundary" rows expressed in acres. Harley Weston lui répond. 





252 x ? is a cube 
20041222 

Andrea pose la question : What is the smallest positive interger by which 252 can be multipled so the result is a perfect cubed? Penny Nom lui répond. 





Making the number 99999 
20041222 

Lisa pose la question : Make as many equations as possible to make the number 99999 using all of the numbers 09 but only once per equation. example 01234 + 98765 = 99999 she needs to make 150+ equations. Paul Betts lui répond. 





A Reuleaux triangle 
20041222 

Bob pose la question : I am trying to remember the name given to the regular figure constructed from three arcs. The figure is like an equilateral triangle except with arcs for each side. Chri Fisher lui répond. 





Divisibility by 15 
20041219 

Lisa pose la question : My son was asked to find divisiblity rules for 15. We have been unable to find the answer. Does it exist? Leeanne Boehm and Denis Hanson lui répond. 





The gradiant of a hill is 9% 
20041218 

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. 





Two intersecting lines 
20041218 

James pose la question : Imagine a vertical line 1.107' tall. Leaving the top of this line, sloping down to the right at a 4:1, at what horizontal distance will the line strike a second line, which leaves the the bottom of the vertical line sloping down to the right at a rate of .02 ft/ft (or 2%)? There is a fairly easy solution to this, but I have lost my notes! Harley Weston lui répond. 





A two equation fact family 
20041217 

Tony and Hailey pose la question : My Daughter Hailey had this question as part of her 4th grade math homework. Name 2 fact families that have only two equations. For the life of me I can't figure it out. Any ideas? Penny Nom lui répond. 





0.999..., asymptotes and infinity 
20041217 

Mike pose la question : My Name is Mike and I teach high school. I had a student ask me to explain why .9 repeating is equal to 1. Then he asked me about an asymptote, or why a parabola or any other curve for that matter can continually approach a value (like 1) and yet never attain a value of 1. He is thinking that these two should represent the same concept and yet they contradict each other. Do you have a solid explanation for him? Of by the way he is a 7th grader. Great little thinker!!!!! Claude Tardif and Harley Weston lui répond. 





2^10 = 1/2^x  1 
20041213 

Randy pose la question : Could you explain to me how the following equation is solved please.
2^10 = 1/2^x  1 Harley Weston lui répond. 





ln(x)/x 
20041211 

Tina pose la question : What is the derivative of (ln x)/x? The double derivative? Penny Nom lui répond. 





A geometric proof 
20041211 

Hanna pose la question : Given: ABCD is a quadrilateral;
Prove: ABCD is a parallelogram Penny Nom lui répond. 





A sequence 
20041211 

Amanda pose la question : Find the nth term of the following sequence
4, 10, 28, 82 Penny Nom lui répond. 





Three calculus problems 
20041209 

Ashley pose la question : Hi, I am having a lot of trouble with three calculus questions and was wondering if you could help Penny Nom lui répond. 





Strings of 4 digits from 1,2,...,7 
20041209 

Tom pose la question : How many different combinations can be made of the numbers 17 in 4 string combinations in any order? EX:7235, 3517, etc...
And if you were to include the same 2 numbers in every combination, how many would that make? EX: Using 1 & 2: 1274, 5142, 2751, etc... Penny Nom lui répond. 





Combinations 
20041209 

Keith pose la question : i have a bucket that can hold 12(or x) number of rocks. if i have 13(or y) rocks how many different combinations of rocks can i put in the bucket without having the exact same 12(or x) rocks in the bucket. is there a formula that can be used for this problem in all cases and if so how and why does it work. Penny Nom lui répond. 





A regular hexagon is inscribed in a circle. 
20041208 

Abraham pose la question : A regular hexagon is inscribed in a circle. What is the ratio of the length of a side of the hexagon to the minor arc that it intercepts?
(1) pi/6
(2) 3/6
(3) 3/pi (This is the correct answer.)
(4) 6/pi
I found the length of the minor arc to be (pi)(r)/3 by doing a sixth of the circumference(2pi r).But I can't find the length of the radius to finish off the problem. If I knew the radius I would then plug it into the above and then use the radius again to be the length of the side because the triangle(one of the six of a hexagon) is equilateral. But can you show me how to get the radius to be 3? Thank you so much.
Walter Whiteley lui répond. 





A belt around two pulleys 
20041207 

Ian pose la question : a belt is stretched around two pulleys whose centers are d units apart and whose radii are R and r respectively (obviously R+r<d). the challenge is to find the length of the belt, l as a formula in terms of R, r, and d only. Penny Nom lui répond. 





An arc of a circle 
20041205 

Ruben pose la question : i have an arc 55 inches wide, 12 inches high at the centerline of the arc. how can i determine the diameter of the circle that would correspond to the arc. Penny Nom lui répond. 





Geometric sequence 
20041204 

Lesa pose la question : Find a formula for the geometric sequence: (√3  √2), (4  √6), (6√3  2√2), … Penny Nom lui répond. 





Probability 
20041204 

A parent pose la question : Consider a 30 sided polygon. If three diagonal are selected at random, what is the PROBABILITY that they share a common endpoint? Denis Hanson lui répond. 





"a" cubed minus "b" cubed 
20041202 

Denise pose la question : "a"cubed minus "b"cubed equal (ab) times
("a"squared plus "ab" plus "b"squared)?
I know this is a formula, but why is it true? Penny lui répond. 





Select a card from the deck. 
20041202 

Heidi pose la question : Select a card from the deck. What is the probability that this card will be red? Show the number of expected outcomes versus the number of total possible outcomes. What type of event does this represent? Penny lui répond. 





1/x + 1/y = 2/31 
20041201 

matt pose la question : I have this problem which I think is a bit more tricky than usual.
x and y are positive integers.
1/x + 1/y = 2/31 Claude Tardif lui répond. 





e = ln(b/a) solve for a 
20041201 

Daniel pose la question : I am trying to make "a" the subject of this equation "e = ln(b/a)" but am not sure if i'm doing it right. Any help would be appriciated, Claude Tardif lui répond. 





The volume of a sphere 
20041130 

Lyndsay pose la question : twenty cubic metres of air are pumped into a spherical hot air balloon with each given diameter: 1.0m; 2.0m; 3.0m; 4.0m; 5.0m;6.0m
a)calculate the new diameter, new suface area, and new volume of each balloon. Penny Nom lui répond. 





The substitution method 
20041128 

A student pose la question : I Was working and i ran into this problem can you help me solve it using the substitution method?
3x2y=10
x+5y=27 Penny Nom lui répond. 





The tangent line at an inflection point 
20041128 

Louise pose la question : the equation of the tangent line to the curve y = x^{3}  6x^{2} at its point of inflection is... Penny Nom lui répond. 





Computing confidence intervals 
20041126 

Christie pose la question : I was given a question with N=100, sample proportion is 0.1 compute the 95% confidence interval for P? I have tried this several ways but do not know how to do without means, standard deviations, standard error of the mean? I asked my teacher and she said I have all the info I need. Can you help???? Penny Nom lui répond. 





A right triangle 
20041124 

Bruce pose la question : In triangle ABC.
Angle ABC is 90 degrees.
Side AB measures 34.
Side BC measures 31.
What does side AC measure? Penny Nom lui répond. 





Slicing cubes 
20041123 

Anthony pose la question : You are working with a power saw and wish to cut a wooden cube 3inches on aside into 27 1inch cubes. You can do this by making six cuts through the cube keeping the pieces together in the cube shape. Can you reduce the number of necessary cuts by rearranging the pieces after each cut? Chris Fisher lui répond. 





Cost before the markup 
20041123 

Norman pose la question : the sum of eg $130 includes the markup of 30%.
However I need to calculate the percentage to apply to the $130 to assess the cost ie $100. Penny Nom lui répond. 





A graph with certain properties 
20041122 

A student pose la question : i was asked as a question in coursework to sketch the graph with the following characteristics:
a double root at 3
a pair of imaginary roots
an xintercept at 6
a root at 4 which is not a double root Penny Nom lui répond. 





Combinations 
20041122 

Vivek pose la question : Show that
10C0 + 10C1 + 10C2 + 10C3+.....10C10 =1024 Penny Nom lui répond. 





The length of an arc 
20041121 

Daryl pose la question : I am tying to find the arc length of a line 6' and the vertex of the arc 1' off of the line. that is all that is known Penny Nom lui répond. 





Is a square a rectangle? 
20041121 

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. 





Proof by induction 
20041120 

Vic pose la question : Problem: Find the first 4 terms and the nth term of the infinite sequence defined recursively as follows:
a(1) = 3 and a(k+1) = 2a(k) for k > 1.
Note: Quantities in brackets are subscripts
> means 'equal to or greater than'.
Using the recursive formula, the first 4 terms are;
a(1) = 3, a(2) = 6, a(3) = 12, a(4) = 24
The nth term a(n) = 2n1 x 3 (equation 1)
Equation 1 must be proven using mathematical induction. This is where I am having a problem. Penny Nom lui répond. 





Solving quadratics 
20041120 

Aaron pose la question : Can you solve the following equation (quote the value of x,y and t to 3 sig figs)
((i have changed figures so that i can work through my own example))
x^{2} + x  6 = 0
5y^{2} +19y = 3
10cos2 t + 3cos t = 4 Penny Nom lui répond. 





Construction of a cone 
20041120 

John pose la question : I am a builder working on a project where I need to make a cone. It's a right circular cone with 15" base radius and slant angle of 30 degrees. I want to cut it out of flat sheet metal then bring the edges together to form the cone. Is this enough information? Penny Nom lui répond. 





A sequence 
20041119 

Liucy pose la question : Find the Nth term:
10 40 90 160 250 Penny Nom lui répond. 





Volume of a box 
20041118 

Catherine pose la question : I need to find a formula to calculate the amount of liquid would hold. maybe the volume or something. its a square box used to hold liquid on a farm . we want to measure how much liquid it can hold. Penny Nom lui répond. 





1/4 tsp salt = ??? grams 
20041116 

Julie pose la question : if i have 1/4 teaspoon of salt how many grams does that equal Penny Nom lui répond. 





Equations involving radicals 
20041116 

Merin pose la question :
I am quite confused about solving radical equations. This is what I understand:
___
V x3 = 3
Then you would square each side to get ride of the radical sign and then you solve the problem from there. (x=12 right?)
However, what about a problem with two radicals? For example:
___ ____
V x2 + V 3x3 = 3
No matter what I try I cant get the right answer!! Please help!!! Penny Nom lui répond. 





Interior and exterior angles of a polygon 
20041116 

Aaron pose la question : How do you find the measure of interior and exterior angles of a regular polygon when you are given the number of sides? Walter Whiteley lui répond. 





Planting trees 
20041115 

Heather pose la question : Design a plan of how it would be possible to plant 10 trees in 5 rows, and have 4 trees in each row. Penny Nom lui répond. 





A fixed point problem 
20041114 

Bob pose la question : I am trying to solve an existence of fixed point problem. I need to show that a function f (on reals) with f'(x)=>2 has a fixed
point. Claude Tardif lui répond. 





An ODE 
20041110 

David pose la question : I have a question that i really cant do, it is as follows:
The ODE dy/dx + 0.5y = 0.5e^(1.5x) ; y(5) = 2
Solve the ODE subject to the given condition using exact methods and evaluate the solution y for x = 5 x=5.2 x=5.4 x=5.6 x=5.8 x=6 Harley Weston lui répond. 





Order of operations 
20041110 

Andrew pose la question : I'm trying to solve this question, and I can't seem to remember the rules back from my high school days.
(40 x 8 ) / 2 + 55  15 =
Can you help me with the answer? Harley Weston lui répond. 





A 40% reduction 
20041110 

Cathy pose la question : I'm having trouble figuring out how to figure a percentage??? it's easy to find what 40% of any given number is, but how would i accurately figure out what is the final number is when i know the number after the 40% has been removed? when i add 40% to this number it obviously is lower than it should
be. the best i could figure is;
x=?40% > x?=40% i'm all confused???? Penny Nom lui répond. 





Bedmas 
20041109 

Fariha pose la question : i have a single line question and am not sure of the method
it would be appreciated if u could send me a method and a solution Q : 1 + 9 / 2 + 5 * 1000
would this be solved by BEDMAS? if not, why? Penny Nom lui répond. 





A standard deviation test 
20041109 

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. 





A 306090 triangle 
20041109 

Amy pose la question : How do you find the length of the hypotenuse of a 306090 triangle when the side opposite the 60 degree angle is 6 inches? Penny Nom lui répond. 





Factoring 
20041109 

Rise pose la question : Q1: a^{2} + 5a + 6
I didn't really understand the purpose of the teacher's steps, but was able to get my daughter to find factors of 6 and then add them together to find which resulted in the sum of 5.
Unfortunately, this problemsolving technique did not help us to solve for the more complex problems as follows:
Q2: 9a^{3}  24a^{2} + 12a Penny Nom lui répond. 





The lcm of 5, 3, 4, 7 and 2 
20041105 

Christine pose la question : what is the lcm of 5,3,4,7,2 Penny Nom lui répond. 





42.5 is what % of 170? 
20041105 

Dawn pose la question : 42.5 is what % of 170? Penny Nom lui répond. 





The points of intersection of two graphs 
20041105 

Benjamin pose la question : How do I find the points of intersection of the two functions:
1) y = 2  ex
2) y = 1 + x2 Harley Weston lui répond. 





Probabilities in poker 
20041104 

Ben pose la question : Please can someone tell me the odds of getting a royal flush while playing texas hold em.
Please can you also let us know the odds of a royal flush while playing texas hold em if you must be dealt two of the needed cards. Chris Fisher lui répond. 





The least common denominator 
20041103 

A student pose la question : Write the LCD for each pair of fractions.
13. 1/3,1/5
14. 2/7,1/4
15. 3/4,3/5 Penny Nom lui répond. 





The lcm of 1 and 1 
20041103 

Nayiyan pose la question : I would like to know what is the LCM of (1) and (+1) is. Penny Nom lui répond. 





Adding 3% to get 120,000 
20041102 

Shaun pose la question : I was asked a question by a friend of mine's kid. He asked me if you had a final figure of say 120,000, how do you work out the amount you started with if you added 3% of the starting amount, to the starting amount to get the 120,000.
Paul Betts lui répond. 





Tennis balls and probability 
20041101 

Jeremy pose la question : I have a hopper of tennis balls that contains 25 new tennis balls and 10 old tennis balls. In the hopper the tennis balls are mixed up randomly. If i take one ball out of the hopper and hit it and then put it back and then take another ball out of the hopper and hit it and put it back, what is the probability that i hit two new tennis balls? Also a tennis ball becomes old after being hit just once. Penny Nom lui répond. 





The sides of a hexagon 
20041101 

Timothy pose la question : I have a perfect Hexagon in which i know the measurement across is 10m. Not from point to point, but from the middle of one side directly across to the middle of the other. From that measurement, how can I determine the length of 1 side. Penny Nom lui répond. 





Multiplying two algebraic fractions 
20041031 

A parent pose la question : Multiply:
x+2 x²4
 x 
x2 x²+x2 Harley Weston lui répond. 





Imaginary roots of a ploynomial 
20041031 

Jennifer pose la question : how to find the roots of a polynomial equation if it would be imaginary? Harley Weston lui répond. 





GCD and LCM 
20041031 

Cartalina pose la question : how do you calculate the "positive difference between the GCF and LCM of two numbers"? Penny Nom lui répond. 





The combined force of two vectors 
20041030 

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 = 8i3j.
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. 





Solving triangles 
20041030 

Allen pose la question : Solve the following triangles.
Given
1. B = 20 Degrees, a = 25, b = 16
2. A = 35 Degrees, b = 2, c = 3
3. A = 32 Degrees, C = 44, c = 20 Harley Weston lui répond. 





Vectors in three space 
20041030 

Jo pose la question : I have two questions that I just cannot visulise and dont know how to get started on them..!
1. Ship X is sailing North at 4m/s and Ship Y is sailing due East at 3m/s. A sailor on Ship X climbs a vertical pole at 1/2 m/s. What is the velocity of the sailor on Ship X relative to an observer on Ship Y? State it's magnitude and direction.
Not sure where to start with this one...
2. Show, using vectors, that for any tetrahedron, the segments joining the midpoints of the opposite edges are concurrent.
i know what a tetradedron is, and what I am proving but do I solve simultaneously for a specific case?? Walter Whiteley lui répond. 





Bedmas 
20041030 

Gina pose la question : I am just curious whether Bedmas would be used in the following question as it is not in the typical Bedmas format.
Multiply 12 x 24
Add 26
Divide by 2
Subtract 7
Would we go about doing it in the sequence it is given or in Bedmas ? Penny Nom lui répond. 





The force of a 5000 tonne lorry 
20041027 

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. 





Ratios and rates 
20041027 

Kenneth pose la question : What is the difference between a ratio and a rate? Penny Nom lui répond. 





Cube roots 
20041026 

A parent pose la question : How do you solve the problem of finding the cubed root of (17 to the power of 3).
Can you show me each step and if you have a visual representation of this it would be very helpful.
Also can you show a step by step of finding the cubed root of 27. Visuals help a lot Penny Nom lui répond. 





20 Golfers 
20041026 

Ian pose la question : I have 20 golfers playing over 6 days I would like to schedule all 20 golfers in 5 groups of 4 on each day here is the catch.... I would like each player to play with each other once during the 6 days. Chris Fisher lui répond. 





The point slope form of a line 
20041026 

Jack pose la question : Given a set of ordered pairs, ie (1,1) (2,4) (3,7), how does one determine the rule f(n) other than by trial and error Penny Nom lui répond. 





Largest square inside a circle 
20041025 

Bob pose la question : my granddaughter asked
what is the largest size square in inches
would fit in a 60 inch circle?
I believe it to be around 42.3 inches but
would like to teach her how to do it mathematically. Penny Nom lui répond. 





Square roots and inequalities 
20041025 

Waheed pose la question : Q1. What is the simplest way of finding a square root of any number using just a pen and paper? (I am asking this question because I browsed a few sites a didn't find any method that is simpler than the one I use. so I am just curious.)
Q2. Is it possible that you take an equation and turn it into an inequality by performing same mathematical operations on both sides? Claude Tardif and Penny Nom lui répond. 





Converting coordinates 
20041025 

Allen pose la question : I am trying to help my son with his home, but I don't remember these conversions. Please help.
1. Convert the following coordinates
Cartesian x = 7, y = 24
2. Convert the following coordinates
Polar r = 4, theta = pi / 3 Penny Nom lui répond. 





Implicit differentiation 
20041024 

Emily pose la question : If x^3+3xy+2y^3=17, then in terms of x and y, dy/dx = Penny Nom lui répond. 





Maximize income 
20041024 

Connie pose la question : A company that sells x units of a product generates an income (I, in dollars) which is a function of x. The income generated is described by the equation
I = (1/2)x^2 + 100x.
Discuss how to determine the number of units that must be sold so that the company can maximize its income. What is the maximum income? Penny Nom lui répond. 





Practical applications: parabolas and Pythagoras 
20041024 

Connie pose la question : Provide two examples of real life objects that incorporate parabolic shapes. Explain the reason why the parabolic shape was used in each object.
I need at least one practical application of the Pythagorean Theorem. Penny Nom lui répond. 





Solve for a and t 
20041023 

Justin pose la question : How do I solve for "a" and "t" in the equations:
1000t= 4000 + 2000t + (1/2)at^2
1000=2000 + at Penny Nom lui répond. 





An aircraft is flying directly from airport A to airport B 
20041022 

A student pose la question : In this question, i is a unit vector due east and j is a unit vector due north. An aircraft is flying directly from airport A to airport B, which is 2000 km from A. The velocity in still air of the aircraft is (150i+50j)km/h and the ground speed is (200i30j)km/h. Calculate
(i) the time of flight, to the nearest min
(ii) the direction of the wind. Penny Nom lui répond. 





The last digit of a large exponent 
20041020 

Landon pose la question : How can one determine the last digit of a large exponent by hand. I have seen several examples of how to do this by breaking it up into smaller exponents, but is there a formula or some common things to look for? Penny Nom lui répond. 





sin(3A) 
20041020 

A student pose la question : Express sin3A in terms of sinA and cosA. Penny Nom lui répond. 





A 40% increase in garage space 
20041020 

Dianna pose la question : A bus company recently expanded and no longer has enough room in its garage for all of its buses. Twelve of the buses have to be stored outside. If the company decides to increase their garage space by 40%, this will give them enough room for all of their current buses, plus enough room to store another twelve in the future. How many buses does the company own? Penny Nom lui répond. 





A square footage problem 
20041019 

Jerome pose la question : I have a peice of property that is almost a triangle but not exactly about 280 frontage with the side lines at 228 and 237
I was told I had about one acre plus a little, a developer says I have 33,000 sq ft. and I would like to know what the real result is Penny Nom lui répond. 





Manipulating exponents 
20041017 

A student pose la question : I was wondering if you can describe the steps in getting the solution to the problem below. I have the solution of 5/3 in the back of a book, but I have no idea how that answer was reached.
2raised to the 100th power + 2raised to the 98th power divided by 2raised to the 100th power  2raised to the 98th power Penny Nom lui répond. 





The third derivative 
20041015 

Holly pose la question : Why would you ever take the third derivative? Harley Weston lui répond. 





A rate of change problem 
20041015 

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. 





Two gears 
20041014 

Lindsay pose la question : "There are two gears, a small one on the left and a larger one on the right. The gear on the right makes 1 revolution. The gear on the left makes two revolutions. Suppose the gear on the right is turned through an obtuse angle. Will the gear on the left make a full turn?" Penny Nom lui répond. 





Divisibility by 7 and 11 
20041013 

Tammy pose la question : I'm stuck in class in Yr 7 And I'm finding it hard on our new topic Divisibility! When I try to find out what this means on Internet sites i can not understand the used symbols like algebra and so on. I'm stuck on the divisibility rules for the number 11! Penny lui répond. 





$25,000 at 11% per year 
20041013 

A student pose la question : suppose u have $25,000 to invest and the interest rate at your bank is 11%.
1) how much money would you have at the end of EACH of the first four years?
1) i already kno that the first year w/ interest is $27,750 but how do i get the 2nd? 3rd? 4th? years? Penny lui répond. 





Pythagoras in everyday life 
20041013 

Tiffany pose la question : I was wondering if you have any reallife uses of the pythagorean theorem that you use in your everyday life. Penny Nom lui répond. 





Cycling in the wind 
20041011 

A student pose la question : A cyclist is travelling in the direction of 12i+5j at a speed of 39 km/h where i is a unit vector due east and j is a unit vector due north. The wind appears to the cyclist to be blowing with a velocity of (4i+j) km/h. Find, correct to 1 d.p
(a) the true speed of the wind and
(b) the bearing from which the wind is blowing
Penny Nom lui répond. 





An Octagon 
20041010 

A parent pose la question : I am trying to determine what the size of each triangle is of a 12 foot circle consisting of 8 triangles would be. I've gotten as far as the radius being 6 feet, but cannot figure the distance. Penny Nom lui répond. 





A five digit number 
20041006 

A parent pose la question : What is the 5 digit number in which the first 2 digits are the square of the 3rd digit and the last 2 digits are the square of the digit that is one less than the third digit? The sum of all the digits is 22. Penny Nom lui répond. 





A common tangent line 
20041005 

Shanup pose la question : The xaxis is a common tangent of y = x^2 and y = x^3. Find the equation of another common tangent. Penny Nom lui répond. 





Direct and inverse variation 
20041005 

Abraham pose la question : Given that y varies inversely as x and x varies directly as z.If z is doubled then y is halved.Why is that true.Please explain.I'm having trouble understanding the different types of variation Penny Nom lui répond. 





Accelerating to the speed of light 
20040930 

Lars pose la question : How long time would it take to accelerate up to the speed of light with an acceleration speed similar to 0100 seconds in 5 seconds? Penny Nom lui répond. 





A mixture problem 
20040930 

Abraham pose la question : A chemist has one solution that is 35% pure acid and another solution that is 75% pure acid. How many cubic centimeters of each solution must be used to produce 80 cubic centimeters of solution that is 50% acid? Penny Nom lui répond. 





A theorem involving a trapezoid 
20040929 

Abraham pose la question : Given:Trapezoid ROSE with diagonals RS and EO intersecting at point M
Prove:Diagonals RS and EO do not bisect each other. Harley Weston lui répond. 





The area of a lot 
20040929 

Deb pose la question : I am trying to figure out how many square feet are in a piece of property. Start at Point Athen go 140 feet norththen 100 feet due eastthen 300 feet at an angle southeast so that connecting to point A would be a straight line (right angle to first line north.) Penny Nom lui répond. 





Visitor wins or home wins 
20040929 

Paavn and Laddi pose la question : I have a math question i am stumped on for one of my classes. The question states that there are 14 baseball games with 2 possible outcomes for each game, visitor win or home win. How many different total combinations are possible from the 14 games? Penny Nom lui répond. 





Cubic yards of concrete 
20040929 

Tanya pose la question : We are starting up a new business and for the business we will be required to order concrete for various shapes. Right now we have a job that requires a concrete slab that a decagon it is 1403/4" from flat side to flat side, 74" from point to center and each flat side is 46" The pad should be 4" thick with 12"x12" continuous footing. Harley Weston lui répond. 





The area of a lot 
20040928 

Stan pose la question : I own a parcel of land (lot 20) that is assessed at 9127.00 square feet and has a frontage of 99.90 feet according to the tax roll. I don't know how large my property actually is since I feel that the tax assessment and the survey map don't jive Harley Weston lui répond. 





A palindrome question 
20040928 

Lilly pose la question : 12, 21, 13, and 31 are the only doubledigit numbers whose squares are the palindromes of the squares of the palindromes of doubledigit numbers. I was wondering why it works for these numbers, and if only these numbers work this way. Chris Fisher and Penny Nom lui répond. 





The length of a rectangle 
20040926 

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. 





37% 
20040926 

Andrew pose la question : how do we change 37% into a fraction Penny Nom lui répond. 





Grams to milliliters 
20040925 

Emily pose la question : I am trying to convert 19.5g into mL assuming that it's water; density=1g/mL. I don't know where to begin. Penny Nom lui répond. 





A parallelepiped 
20040925 

Aman pose la question : " If OA, OB, and OC are three edges of a parallelepiped where O is (0,0,0), A is (2,4,2), B is (3,6,1), and C is (4,0,1), find the coordinates of the other vertices of the parallelepiped.)" Penny Nom lui répond. 





The last digit of 2^28 
20040925 

A student pose la question : I am currently enrolled in a math reasoning class and a math question I have to answer is determine the units digit in 3 28power. When I set up a table and keep cubing the numbers, I find a pattern with the last digits of the numbers that follow 1,3,9,7. My calculator gets to about the 19th power, and then I get an error. If I continued the pattern, would the units digit then be the last digit of 3 28th power, which would be a 7? Please let me know if I am solving this correctly and what a unit's digit actually is. Penny Nom lui répond. 





Rational expressions 
20040924 

A student pose la question : In general, I understand rational expressions except when it comes to solving problems such as:
x+y/2xy  2x/y2x or m4/3m4 + 3m+2/43m
I am confounded by the issue of having to find a common denominator. For example, if I tried to solve these problems by multiplying both denominators they would still be uncommon. Claude Tardif lui répond. 





Supplementary angles 
20040923 

Rosemary pose la question : Is the term supplementary angles only applicable to 2 angles (ie. a pair of angles) or can it be used when talking about 3 or more angles that add to make 180 degrees? Penny Nom lui répond. 





Incremental variance 
20040923 

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 quarterhour 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 volume of a pile of mulch 
20040922 

Sam pose la question : Is there a formula to determine the cubic feet of something in a pile. IE I need to determine the cubic feet of a pile of mulch. The pile comes to a peak, so the length and width decrease as the pile increases. Penny Nom lui répond. 





Four and five digit numbers 
20040921 

Josy pose la question :
The question I have now in front of me is....Is a 4digit number always less than a 5digit number?
Hi Josy,
The digits in order are 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9. Thus the largest four digit number is 9999. The smallet 5 digit number is 10000.
Penny
Go to Math Central
Penny Nom lui répond. 





1,3,6,11,18,29,__ 
20040921 

Guillermo pose la question : How do you get to the answer of this sequence
1,3,6,11,18,29,__ Claude Tardif lui répond. 





f(x) = x4 if x<2 
20040921 

Dani pose la question : Hi, my name is Dani. I'm in tenth grade Algebra 2, and I'm learning about a lot of different kinds of functions, and I can't quite seem to understand how every part of the piecewise function works. I understand most of it, I think, but I've been looking at an example in my math book, and I'm not sure how they got the answer they did. The part I don't understand reads: "Graph f(x) = x4 if x<2" and "Identify the domain and range." The picture in the book shows an open circle at (2,2), with an arrow going down and to the left with the slope being one. How did they get the open circle to be at (2,2), and why does the arrow point where it does? Penny Nom lui répond. 





The method of substitution 
20040920 

Kayla pose la question : y=x1
y=2x3 Harley Weston lui répond. 





Wages for one month 
20040920 

Janet pose la question : if offered $10,000 or 1 cent on the first day and then doubled daily for one month which would you take ? Harley Weston lui répond. 





B={A,{A}} 
20040920 

Muhammad pose la question : Let A be a set and let B = {A,{A}}.
(a) Explain the elements of set B (with some example)
(b) Prove that A is not a subset of B. Penny lui répond. 





The hypotenuse of a right triangle 
20040920 

Shannon pose la question : I am trying to find the hypotenuse of a right triangle with only the length of the opposite side. What is the formula as I don't have the length of the adjacent side? Can I compute it without knowing what the other two angles are? Penny Nom lui répond. 





Fabricating with pipe 
20040919 

Gil pose la question : I need to fabricate a 10 section, 4" pipe circle with an inside diameter of 40". I would like to know what angles would apply and how to find them, Penny Nom lui répond. 





A binomial squared 
20040919 

John pose la question : Can you explain the steps
for me, that get you from (a  b)^{2} to a^{2} 
2ab + b^{2} Penny Nom lui répond. 





Perimeter and area of a semi_circle 
20040918 

A student pose la question : I want to know how to find the perimeter and area of a semicircle and a quartercircle. Penny Nom lui répond. 





Zero to the zero 
20040918 

Greta pose la question : My name is Greta, and I am a 7th grader and my test is coming up. The question I would like to ask you is why 0 elevated to 0 is unidentified. Penny lui répond. 





Driving me crazy 
20040918 

Jerry pose la question : This is driving me crazy!!! Someone told me of a number that can be divided EQUALLY by each of the following individual numbers: 1,2,3,4,5,6,7,8,9. what is that number? Penny lui répond. 





The price of a book 
20040918 

Dorly pose la question : If the number of toonies required to buy a book is nine more than the number of
fivedollar bills required to buy the same book, determine the cost of the book. Penny lui répond. 





A challenge 
20040917 

Lasse pose la question : xy
xx
xyx
xxx
xyxx
"x" and "y" each represents a number.
Find out the system to make the next line Penny Nom lui répond. 





Some numbers less than 100 
20040917 

Paul pose la question : for how many numbers less than 100 is the digit in the ones place half the digit in the tens place? Penny Nom lui répond. 





Division with and without units 
20040917 

Kenneth pose la question : What does it indicate when the divisor has units (dollars) but not the dividend, as in 500/$10.00 or 500 is divided by $10.00?
Are the units understood to be there? Does 500/$10.00 make sense? Penny Nom lui répond. 





The length of a cut 
20040917 

Florita pose la question : My daughhter, who is a 9th grader is attempting to cut a piece of wood after determining the length of the cut for the hypotenuse. These are the measures:
a=4squared, b=6squared.
She determined that c should equal 52. But when she measured the actual piece to be cut, c measured 39.5 inches! Can you offer any insight as to what she is doing wrong? I have suggested that she may be working with an Acute rather than a Right angle . But she insists that it is a Right angle after using a "framing square". Claude Tardif lui répond. 





Pizza for Jack? 
20040916 

Grace pose la question : Jack is playing pool with Jim for $1 a game. He has only $2 and decides to play until he goes broke or has $5, at which point he will quit and go out for a pizza with Jim(Dutch treat). Jack knows from past experience that he beats Jim 60% of the time. What is the probability that Jack will get to eat pizza? Hints: Let A be the 6x6 matrix defined by A=[aij], where aij is the probability that Jack will have $(i1)after one game is he starts with $(j1). For example, a23  .40 since there is a 40% probability that Jack will end up with $1 after a game is he starts the game with $2 (If Jack wins 605 of the time, he must lose 40% of the time). Also, for example, a52 = 0 since there is no way jack can have $4 after one game if he had $1 at the beginning of the game. Since Jack will stop if he goes broke or accumulates $5, a11 and a66 are both 1.
Let x0 = [0 0 1 0 0 0 ] transposed, which we interpret as saying that initially Jack has $2 with a probability 1. Then Ax0 will represent the porbability of each amount of money, $0$5, after one game. What is the probability that Jack will be able to eat pizza by computing Akx0 for large k and finding a limiting value. Penny Nom lui répond. 





Volume 
20040916 

Jonathan pose la question : I have an area of 22ft x 43 ft, 6 inches high
Sq. ft..946
sq. yds...105.1
What is the cubic feet and cubic yards for this dimension. Penny Nom lui répond. 





S is between T and V 
20040916 

Reuben pose la question : S is between T and V. R is between S and T. T is between R and Q.
QV=18 QT=6 and TR = RS = SV Make a sketch and answer the following:
Find RS QS TS TV Penny Nom lui répond. 





The game of 24 
20040916 

Angelica pose la question : how can you make 24 out of 7,7,6,5? Claude Tardif lui répond. 





Finding the height of a triangle 
20040914 

A student pose la question : I have to calculate the height of a triangle.
The base is 6 (units)say ab
One of the top sides is 4 (units)say ca
The other side is 2 (units) say cb
I don't know the angles.
How to find the height? Chris Fisher and Penny Nom lui répond. 





The game of 24 
20040914 

Alan pose la question : I was playing that math 24 game and i cant get 21,14,2,2 to equal 24 Claude Tardif lui répond. 





Crossword math puzzle 
20040914 

Joyce and Tiffany pose la question : The puzzle name was real number vocabulary and the question is (a number that divides evenly into another what is it?). (Space in between ticmarks on a number line). Harley Weston lui répond. 





Payment plus interest 
20040914 

Penny pose la question : Brian wants to borrow some money from Margaret.
After three years he is to pay X back plus one interest sum of 25%. If he is pays back a total of $3800, what was the original sum borrowed? Penny Nom lui répond. 





differentiate Y=X^X^X 
20040913 

Kunle pose la question : differentiate Y=X^X^X Penny Nom lui répond. 





Making a pyramid 
20040912 

Jacob pose la question : My name is Jacob and I am a 11th grade student trying to build a pyramid for a friend but I need a chart of some sort to show me the measurements (I learn better w\pictures) it is a square base with 18 in sides and I want the vertex to be 18in above the base I need to know as many measurements as you can give me. Penny Nom lui répond. 





A copper sphere 
20040912 

Irfan pose la question : The radius of a copper sphere is 3cm. If a wire of 0.4 diameter is drawn by melting it,what is the length of this wire? Penny Nom lui répond. 





Three word problems 
20040912 

Adrian pose la question : 1. Increasing area
of a field: Julia's soybean field is 3m longer than it is wide. To
increase her production, she plans to increase her to increase both the
length and width by 2m. If the new field is 46m2(2nd power) larger
than the old field, then what are the dimensions of the old field?
2. Width of a Football Field: If the perimeter of a football
field in the NFL including the end zones is 1040 ft and the field is
120 yd long, then what is the width of the field in feet?
3. Fencing dog pens Clint is constructing two adjacent rectangular
dog pens. Each pen will be three times as long as it is wide, and the
pens will share a common long side. If Clint has 65 ft of fencing, what
are the dimensions of each pen? Penny Nom lui répond. 





Number combinations 
20040910 

Angela pose la question : I need the number of possible number combinations, both 3 and 4 digit, from 059
I know that 09 has 10000 combinations for 4 digits
I also know that 09 has 1000 combinations for 3 digits
Perhaps you could explain an easier way to figure this out rather than writing all these numbers down?? Penny Nom lui répond. 





A schedule for 6 teams 
20040910 

Greg pose la question : I have a schedule I need to make of 6 teams. They must play each other once however no team can be the away team twice in a row. There must be 3 home games and 3 away games for each team. Penny Nom lui répond. 





105.6 is a discount of 12% from x 
20040910 

David pose la question : If I know that 105.6 is a discount of 12% from x, how do I find x?? Penny Nom lui répond. 





1+3+5+...+(2n+1) 
20040910 

Emma pose la question : Prove that 1+3+5+...+(2n+1)= (n+1)^{2} Penny Nom lui répond. 





Safe cracker 
20040909 

Adam pose la question :
Franklin's friend had taken an item from him, and put it in his family's safe, when franklin went to retrieve it he came to a combination lock on the safe, with the dial numbers going from 0 to 59. Unfortunately, he wasn't sure whether there were three or four numbers in the combination, or even which direction to turn the wheel
If it takes him 15 seconds to try a single combination, how many days will it take him to to try every possible combination? Please round to the nearest day. Penny Nom lui répond. 





The 24 game 
20040909 

Erik pose la question : Ive spent around 40 hours on this one problem. I need help. 3,3,7,7 Claide Tardif lui répond. 





A travelling salesman 
20040909 

Liz pose la question : A salesman traveled due west from city A to city B. The distance he traveled, that is the ditance from A to B, was X miles. He returned from B to A and found that he had traveled half the distance, X/2 miles. How can that be? Chris Fisher and Penny Nom lui répond. 





Crossing a river 
20040909 

Barb pose la question : Nine men and two boys, trekking through the jungle, need to cross a river. They have a small inflatable boat and it's easy enough to row it across the river. The boat, however, can hold no more than one man or the two boys. How can they all get across? (Hint. suppose there was only one man and two boys) Does it make math sense and what would the answer be Penny Nom and Claude Tardif lui répond. 





An inverse 
20040909 

Hillary pose la question : I cannot figure out the inverse of this function.
f(x)= 1/2x 1 Penny Nom lui répond. 





Half way between 
20040908 

Ben pose la question : Find the number halfway between the number shown
751,843 Penny Nom lui répond. 





The nth term 
20040908 

Alex pose la question : What is the nth term?... Like what is it?, How do I find it?, and how exactly is used?... Penny Nom lui répond. 





d varies inversely with g 
20040907 

Ashlyn pose la question : d varies inversely with g when d=8 and g=2
a. write d as a function of g using function
notation.
b. find d(10). Penny Nom lui répond. 





Constructing a cone 
20040907 

Steve pose la question : I am trying to build crayfish traps; one of the components is a cone shaped entry section.
The cone I want to make would be 12" in diameter at the base and 12" in height, from base to peak.
I need a formula to calculate the dimensions and a method of transferring the shape onto a flat piece of material.
Harley Weston lui répond. 





The intersection of planes 
20040907 

Joshua pose la question : I was wondering about the intersection of planes. Can planes intersect? Penny Nom lui répond. 





The bar over repeating digits. 
20040907 

Debbie pose la question : I would like to know the name given to the bar that is written over the repeating digits of a decimal. Penny Nom lui répond. 





How to dry matches 
20040906 

Liz pose la question : The neighbors of a young man who needed seclusion for a few days offered him the keys to their cabin in Maine. Arriving there on a damp and cold autumn evening he saw that while the cabin had normal running water and electric lights, for heat it had only a potbellied stove. Fortunately, there was plenty of wood, kindling, newspaper, and matches. Being an experienced hand at making a fire, he opened the damper, put into the stove crumpled newspaper, and properly stacked the kindling and logs. The matches, however, wouldn't light. They were too damp from the humidty. The nearest town was 30 miles away, and, anyway, it was late. What next? Claude Tardif lui répond. 





(2x+5y6) + (3x4y+12) 
20040904 

GG pose la question : I am a grade 9 student and i do not understand a question. Plz help!
OK here it is........ (2x+5y6) + (3x4y+12) Penny Nom lui répond. 





Order of operations 
20040904 

Leanne pose la question : 6 + 3  2 x 3 = Claude Tardif lui répond. 





The distance formula 
20040904 

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. 





Nine minutes 
20040902 

A student pose la question : You have two hour glassesone measures 7 minutes and one measures 4 minutes.How can you time 9 minutes? Penny Nom lui répond. 





Cubic yards 
20040901 

Garnet pose la question : I have the dimensions of 16 feet by 10 ft and 3 1/2 inches deep how much concrete do I need. Penny Nom lui répond. 





An isosceles trapezoid 
20040831 

Bruce pose la question : An isosceles trapezoid with bases of lengths 12 and 16 is inscribed in a circle with a radius of 10. The center of the circle lies in the interior of the trapezoid. Find the area of the trapezoid. Penny Nom lui répond. 





Cubic meters 
20040831 

Brad pose la question : I have a 10' x 10' x 12" area & need to find the cubic meters, how do I do this? Penny Nom lui répond. 





Percentage change 
20040830 

Lauren pose la question : if egg A weighed 55.4g and after 2 days it weighed 60.9g how could i calculate the percentage change in weight? Penny Nom lui répond. 





Solve for z 
20040830 

Ana pose la question : Solve for z when 4x + 10yz = 0
solve for z if y2 + 3yz  8z  4x = 0?
Do I have to solve all of the variables in order to get z? Penny Nom lui répond. 





69 is what percentage of 113 
20040828 

Mary pose la question : How do I work out what percentage of 113 69 is? Penny Nom lui répond. 





GCD (a + b , a^2  ab + b^2) 
20040827 

Carol pose la question : Let a and b integer and relatively prime. Proof that:
GCD (a + b , a^2  ab + b^2) = 1 or 3 Penny Nom lui répond. 





A big number 
20040826 

Mark pose la question : If you have $999,999,999,999,999,999,999,999,999,999.99 and you find a pennie how much is that and can you give me the name of it. Penny Nom lui répond. 





Combined operations 
20040826 

Louise pose la question : Question 2 1/4 x 1/8 / 1 3/4 x 12 4/9 x 3 = Penny Nom lui répond. 





Percentage of a quota 
20040826 

Jenni pose la question : I have the year to date sales of $2,042,744 and the quota is $2,257,440, how do I figure the percent quota. Penny Nom lui répond. 





The area of a quadrilateral 
20040825 

Rich pose la question : I would like to know how to measure the area (the formula) of a quadrilateral. Penny Nom lui répond. 





The radius of a circle 
20040824 

Peter pose la question : If you slice any circle with a line, and call the distance of the line between intersections the "y" length and the perpendicular length to the shorter side of the curve the "x" length, what is the resulting equation for the radius? Penny Nom lui répond. 





50/5x  y 
20040822 

Rick pose la question : Niece has a question that was marked wrong but we are unable to determine how the teacher calculated and arrived at the answer? The problem was as follows:
50 / 5x  y =
x=5
y=1 Harley Weston and Leeanne Boehm lui répond. 





The area of a lot 
20040822 

Cassie pose la question : I'm in the process of purchasing some land and I'm trying to figure out the square footage of the property. Unfortunately, it's be a while since I had to remember this type of formula. The property is 140 ft on left side, across the back it is 220.61 ft, the right side is 167.52 ft, the frontage is 105 ft. Penny Nom lui répond. 





15 cubic yards of dirt 
20040822 

Barry pose la question : My question...what is the equivalent of 15 cubic yards of dirt? Penny Nom lui répond. 





130 cc. is ? 
20040820 

Ayrn pose la question : 130 cc. is ?
I have to put 130cc. of petroleum in a bucket how much exactly is that?
Also 110 cc.?
I have to also put 110cc. wood alcohol in a bucket aswell! Penny Nom lui répond. 





Golfing with Norm 
20040819 

Norm pose la question : I am organizing a golf tournament with 6 American and 6 Canadian players. We play 3 rounds of golf. Is there any way to arrange that everyone plays without playing with the same person twice. Each foursome must consist of 2 Americans and 2 Canadians with one of each in a cart. Your help would be much appreciated. Claude Tardif lui répond. 





Golfing with Sally 
20040819 

Sally pose la question : We are a group of 8 golfers (2 foursomes) and want to golf 3 games together. How can we arrange it so that we all get to golf with each other at least once?
At another venue, we have 18 golfers (3 foursomes, 2 threesomes) and want to golf 6 games together. Same question, how can we arrange it so that we all get to golf with each other at least once? Claude Tardif lui répond. 





A division symbol 
20040818 

William pose la question : i was wondering what the mathematical name for this division sign (÷). Penny Nom lui répond. 





A cube is inscribed inside a sphere 
20040818 

A student pose la question : A cube is inscribed inside a sphere with radius sqrt8cm. Find the
(a) length of the cube
(b) volume of the space inside the sphere but outside the cube. Penny Nom lui répond. 





The series from i=1 to n :ai 
20040818 

Ken pose la question : a.) Explain the difference between
the series from i=1 to n :ai
and the series j=1 to n :aj
b.) Explain the difference between
the series from i=1 to n:ai
and the series from i=1 to n :aj Penny Nom lui répond. 





Area of a triangle 
20040817 

Barkie pose la question : I'm going into tenth grade and I have a triangle who's sides measure 3ft, 4ft, and 5ft. I need to find the area however I don't know the height, or how to get it. Chris Fisher lui répond. 





Two water jugs 
20040816 

A student pose la question : You go to a source of water with two jugs and only two jugs. One jug has a capacity of exactly three pints and the other five pints. Both jugs are opaque (you can`t see inside them) and irregularly shaped. You have no other water containers. You do not have a scale. How can you use the two jugs and only the two jugs to measure exactly four pints of water? Penny Nom lui répond. 





Percentiles 
20040815 

Gary pose la question : Table 1
Selected percentiles for family income in the US in 1992
1 $1,300
10 $10,200
25 $20,100
50 $36,800
75 $58,100
90 $85,000
99 $151,800
Q. The percentage of families in Table 1 with incomes below $58,100 was about? Penny Nom lui répond. 





A probability question 
20040815 

Gary pose la question : In a law school class, the entering students averaged about 160 on the last
LSAT; the standard deviation was about 8. The historgram of the lLSAT
scores follwed the normal curve reasonable well.
Q. About what percentage of the class scored below 166?
Q. One student was 0.5 above average on the last LSAT, about what percentage
of the students had lower scores than he did? Penny Nom lui répond. 





X is due north of Y ... 
20040811 

A student pose la question : X is due north of Y and 2km distant. Z is due east of Y and has a bearing of S35°12'E from X. How far, to the nearest metre, is Z from X? Penny Nom lui répond. 





Cubic yards of dirt 
20040811 

A parent pose la question : How many cubic yards of dirt would it take to fill an area that is 325 feet by 325 feet and is 3 feet deep? Penny Nom lui répond. 





Acres and miles 
20040811 

A student pose la question : How many acres are in 1 mile? Penny Nom lui répond. 





2.79 acres 
20040811 

Helen pose la question : What would the square footage be of 2.79 acres? Penny Nom lui répond. 





Area of a hexagon 
20040810 

RB pose la question : Hello. I need to find the Area in sq. ft. of a Hexagon with 6 equal sides, of 26' each. Penny Nom lui répond. 





A conic 
20040810 

A student pose la question : My question is about this equation 32x*2 18y*2 64x +72y +248 =0
explain why as x goes to the infinity the graph of the conic looks like y= (3/4)X.
What I did to try to find the solution of this problem was to graph and then I thought that maybe trying to find the equation of the asymptotes I could do it, but it was useless because the equation of the asymptotes is y= +4/3(X1) 2 and that does not explain why tho conic looks like y=(3/4) x . I would really appreciate your help on this. Penny Nom lui répond. 





Constructing a triangle 
20040808 

KV pose la question : HOW TO CONSTRUCT A TRIANGLE ABC, WHEN
ITS ALTITUDES AD,BE,CF ARE GIVEN Chris Fisher lui répond. 





A big number 
20040808 

Carter pose la question : Can you tell me what number this is?
10,000,000,000,000,000,000,000,000,000,000,000,000
Where can I find the names for big numbers? Penny Nom lui répond. 





Limits and composite functions 
20040807 

Sue pose la question : I have two questions, one about a limit and the other about a composite function. If you could help me, I'd really appreciate it.
1. Find the limit:
lim[x>0] (x*csc(x))
I converted csc(x) to cos(x)/sin(x), but I didn't know what to do after that.
2. f(g(x)) = ln(x^2 + 4), f(x) = ln(x^2) and g(x) > 0 for all real x, find g(x):
I'm having trouble with this one because x^2 + 4 isn't a perfect square.
Sue Penny Nom lui répond. 





The integrating factor method 
20040805 

A student pose la question : Whilst using the integrating factor method, I am required to integrate a function multipled by another function.
say f(t) = exp(kt) and some other function g(t); where exp = exponential and k is some constant.
Integral f(t)*g(t) dt or
Integral exp(kt)*g(t) dt
What would the result of this integral be? I have never met an integral like this before. Would it simply be exp(kt)*g(t)/k?
More specifically, the problem and my attempted answer is in PDF format:
In my attempted solution, I am unsure about the last two lines I have written out, as it relates to integrating a function multipled by another function. Harley Weston lui répond. 





Integrating e^sin(x) 
20040804 

A student pose la question : I need to know that how to solve the integral " e^sin x", Harley Weston lui répond. 





Differentiation 
20040804 

A parent pose la question : I am a parent trying to understand higher level of maths and would be very grateful if you could help with differentiating the following functions, identifying general rules of calculus:
a) f(x)=e^2^xIn(cos(8x))
b) f(x)=secx/SQRTx^4+1 Penny Nom lui répond. 





Two trig problems 
20040804 

Tracie pose la question : sin^2x  sin x 12 = 0
sin 2x = sin x Penny Nom lui répond. 





When is the limit of f(x) undefined? 
20040803 

Nicolasa pose la question : When is the limit of f(x) undefined? Penny Nom lui répond. 





an integer with three factors 
20040803 

A student pose la question : What is the probability that a randomly chosen 3 digit number has exactly 3 factors Penny Nom lui répond. 





sin^2x5sinx3=0 
20040802 

Kerri pose la question : hey my name is kerri i'm a college students and i was wondering if you could help in with this problems
sin^2x5sinx3=0 Penny Nom lui répond. 





A tangent to a hyperbola 
20040802 

A student pose la question : The equation of a hyperbola is 32x*2 18Y*264x +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 problems 
20040802 

JJ pose la question : A question on my homework assignment about logs says "suppose that x=logA and y=logB & write the expression in terms of x and y"
log(A  B)
Is this even possible? It seems like a typo.
Another is: "solve for t."
12(1.221)^t = t + 3
Is this one possible? If it is, I cant figure it out. Penny Nom lui répond. 





A trig problem 
20040802 

A student pose la question : Given that the maximum value of [sin(3y2)]^2 [cos(3y2)]^2
is k. If y>7, Find the minimum value of y for which
[Sin(3y2)]^2  [cos(3y2)]^2 =k. Penny Nom lui répond. 





Domain and range 
20040801 

JJ pose la question : I'm checking domain and ranges of these functions. Are these right? Penny Nom lui répond. 





The law of sines 
20040801 

Joy pose la question : How do you solve this? Do you solve this triangle using the law of sines of the law of cosines? (ASA)
A=120DEG. B=40DEG c=35 cm
I keep getting different answers. Penny Nom lui répond. 





Rate of change problems 
20040801 

Jim pose la question : I just want to check a couple average rate of change problems because i just guessed on how to do them. Can you tell me how to do them?
the question says if f(x) = sqrt(x + 3), find f( x + rx). I got sqrt( x + rx + 3)
the other two are : f(x)= 3x1 (f(x)  f(1)) / (x1) ... I GOT 3 &
f(x)= x^3  x (f(x)  f(1)) / (x1) ... I GOT x^2 + x Penny Nom lui répond. 





Combien de litre y a t'il dans un M3 
20040730 

Un eleve pose la question : j'aimerais savoir combien de litre y a t'il dans un M3. car je dois mettre un produit spécial dans une piscine. Claude Tardif lui répond. 





A parallelogram 
20040730 

Keith pose la question : I'm a high school student and have been having trouble with this problem , which is based on one pair of parallel sides of a parallelogram: If AD = 6x5 and BC = 3x+7 find x. Of course both sides have to be equal. Now I know the value of x is 4 So my question is how do you get 4 from the given information. Penny Nom lui répond. 





Extraneous solutions 
20040728 

Nicole pose la question : When I have a problem like (2x + 3)/5 = (x + 1)/6 and the question asks to check for extraneous solutions, how do you solve that? Penny Nom lui répond. 





Water in a cone 
20040728 

A student pose la question : A vertically inverted cone( i.e. vertex down) has a radius 7
inches and height 24 inches. Water is filled to one third of its
height .Find the ht of water when cone is turned upside down Penny Nom lui répond. 





The third side of a triangle 
20040728 

Annette pose la question : How do you find the length of a triangle side if you know two sides? Penny Nom lui répond. 





Factoring 
20040728 

Nicole pose la question : Can 4x2 + 19x + 12 be factored? i have tried but i cannot figure it out. Is there a way to find out if it cannot be factored before i try to work out the problem? Penny Nom lui répond. 





The intersection of two graphs 
20040728 

JJ pose la question : Is there a way to find the intersections of these graphs algebraically?
x^2 + y = 4 & 2x  y = 1
I got (1.45, 1.9) and (3.45, 7.9) with a graphing calculator.
AND THESE...
y = 3.29x & y = 5.5(x^0.5)+ 10000
I got x at 3133 with a graphing calculator.
Penny Nom lui répond. 





x^2 = x + 2 
20040726 

A parent pose la question : x2 = x+2
My daughter came home with this equation today and although I know the answer is x=2, i have no way of proving it by showing any working out. Penny Nom lui répond. 





The railing around a pool 
20040726 

Bob pose la question : I have a 15' circular above ground pool. Around the perimeter of the pool are eleven (11) sections of railing. Each rail has 5 slots at each end for pins. I have calculated that the length of the arc under the railing to be 51.4". what I am trying to determine is the distance between the end points of the arc so that I can figure out which slot to use in the rails without going round and round the pool moving and removing the rails until they finally fit. Been there, done that, no fun. Penny Nom lui répond. 





The pvalue 
20040725 

Kathy pose la question : Ms. Lisa Monnin is the budget director for the New Process Company. She would like to compare the daily travel expenses for the sales staff and the audit staff. She collected the following sample information.
At the .10 significance level, can she conclude that the mean daily expenses are greater for the sales staff than the audit staff? What is the pvalue?
Having problems finding the pvalue & unsure of the formula.
Kathy Penny Nom lui répond. 





Row echelon form 
20040724 

Michael pose la question : My name is Michael and I'm in the 11th grade. I have a Math question that I can't solve. The problem is system of equations that I need to do in augmented matrix form, find the row echelon form, and solve it by using back substitution.
2x + 3y + 7z =13
3x + 2y  5z = 22
5x+ 7y  3z = 28 Penny Nom lui répond. 





The inverse of a quintic function 
20040722 

A student pose la question : I'm really having trouble finding out the inverse of this quintic equation. F(X)= X^{5}+3X^{3}+1.I know that this quintic has an inverse because it is one to one. But I can't find a method to solve this. Finding the inverse of a quadratic or a cubic equation is a lot easier, but with this quintc I am really lost. I even know how the graph of this equation and its inverse looks like, but I'm not sure if Iam getting the right equation. Please help me out. Penny Nom lui répond. 





Factoring 
20040719 

A student pose la question : Factor completely:
3x3  24y3
54x6 + 16y3
16xy  4x  4y  1
0.09x2  0.16y2 Penny Nom lui répond. 





The number of blocks in a mile 
20040718 

Valerie pose la question : I don't know if you can help me but I was wondering how many blocks are in a mile in Ocean City, New Jersey? Penny Nom lui répond. 





A proof in geometry 
20040716 

An pose la question : Im taking a geometry course for the summer , and we just started to learn about proofs for about one week. Today in class, we started to do this one proof but didnt finish it because class ended. the problem is as follows. Penny Nom lui répond. 





Solving some quadratic equations 
20040715 

A student pose la question : Could you please solve the following for x
x^{2}+6=5x
x^{2}+16=8x
2x+21=3x^{2} Penny Nom lui répond. 





Two vector problems 
20040714 

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 commuter 
20040714 

JJ pose la question : A student who commutes 27 mi. to college remembers, after driving a few minutes, he forgot a term paper. Driving faster than usual, he returns home, gets the paper, and once again starts to school. Sketch the graph of the student's distance from home as a function of time.
Does it mean that the student drives at normal speed, drives faster to pick up the paper, and resumes normal speed to head back, or that the student drives at normal speed, then drives faster the rest of the way to college? Penny Nom lui répond. 





12(1.221)^t = t + 3 
20040714 

Jay pose la question : This problem has me stumped since i cannot separate the t and the 3. Here it is:
12(1.221)^{t} = t + 3
It's on a logarithm worksheet, but how do i figure it out?! Harley Weston lui répond. 





Two puzzles 
20040713 

Fred pose la question : A young man's car developed a flat tire while he was driving along a deserted street. He pulled over to the curb and did all the usual things; removed the hub cap; unscrewed the lugs and rested them carefully in the hub cap, jacked up the car. As he was putting the spare tire onto the axle he accidentally kicked the hub cap. The lugs rolled out, and all five of them rolled down a nearby grate. Peering through the bars of the grate the man thought he could see the lugs about 6 feet below in a shallow water puddle. He had a problem, how do you think he solved it?
It is noon, your lunch hour, but you can not go out because there is a terrific hailstorm. Turning on your radio you hear the weathercaster predict that the hail will change to rain and that it will pour all day today. How can you determine the sun will be shining in 36 hours? Justify your answer. Penny Nom lui répond. 





An Octagonal playhouse 
20040713 

Levi pose la question : I'm building an octagon playhouse for my son that is 8 feet wide.
what would be the measurements of each of the eight sides. Harley Weston lui répond. 





Cubic yards 
20040712 

A homeowner pose la question : I would like to know how many cubic yards are in the following; 20 ft wide x 80 ft long x 4 inches thick?
I am trying to figure out how much concrete I will need to pour for a driveway. Penny Nom lui répond. 





x = 2^x 
20040712 

A student pose la question : If the graphs of y=x and y=2^{x} are drawn on the same set of axes, they will intersect when x is equal to what?
(1)1
(2)2
(3)0
(4)They won't intersect.
I know the answer is number 4 by graphing which is permitted; however, I would like to know if there is any algebraic way to do this type of problem.If yes, please show me how.Thanks. Penny Nom lui répond. 





Two Problems 
20040712 

Justina pose la question : i cant figure out the range of this equation in interval form because the highest point seems to be a decimal. please help f(x) = x + sqrt(4x2)
.............................................................................
Building Design A circular air duct of diameter D is fit firmly into the rightangle corner where a basement wall meets the floor (see figure). Find the diameter of the largest water pipe that can be run in the rightangle corner behind the air duct. Claude Tardif and Penny Nom lui répond. 





The tangent of theta 
20040710 

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. 





Four digits 
20040710 

Rob pose la question : I am always interested to know how the for digit works. I mean, you have correctly put it that the total numbers obtain from 0000 thru 9999 are 10,000. My question is, is there any simple formula to turn this simple 4 figures of say: 1234. Penny Nom lui répond. 





The circle through three points 
20040706 

Jim pose la question : I am a student trying to solve math problem. I'd like to calculate the radius of the circle that exactly fits any three points. If the points are (X1,Y1), (X2,Y2), and (X3,Y3), what is the radius of the circle that contains those three points? Penny Nom lui répond. 





Vectors 
20040706 

Annie pose la question : a=3ij+2k and b=i+3j2k, determine the magnitude and direction cosines of the product vector and show that it is perpendicular to a vector c=9i+2j+2k. Chris Fisher lui répond. 





An ineqlality with absolute values 
20040705 

Uneeza pose la question : abs(x^{2}  4x) > 3 Claude Tardif lui répond. 





Factoring integers 
20040702 

A student pose la question : After looking at all the info I could get about NFS, I still have some questions that are unsolved:
First of all: If someone found an algorithm that has a worst case running time of N*Log(N) to factor an integer n into his divisors, would it be quicker or slower then the number field sieve algorithm?
secondly, what exactly is the time complexity of the Number Field Sieve algorithm, if I would factor an integer n? Claude Tardif lui répond. 





Choosing 5 numbers from 1,...,36 
20040630 

A lottery player? pose la question : how many combinations are there for the numbers 1thru 36 when only using each number once in groups of five Penny Nom lui répond. 





Simplify 
20040627 

Tiff pose la question : Simplify:
3x (x2 + 2)
(x + 2) (x + 3) Penny Nom lui répond. 





Aunt Lucy's letter 
20040627 

Olivia pose la question : "Dear bob,
now that i am getting on (70 today). i want to give you some of my money, i shall give you a sum each year, starting now. you can choose which of the following schemes you would like me to use.
a) £100 now, £90 next year,£80 the yaer after and so on.
b) £10 now, £20 next year, £ 30 the next year and so on.
c) £10 now, 1.5 times as much next year, 1.5 times as much the year after that and so on.
d)£1 now, £2 next year, £ 4 the year after, £8 the year after and so on.
of course these schemes will only operate while i am alive. i look forward to hearing which scheme you choose and why!
Best wishes,
Aunt Lucy." Penny Nom and Claude Tardif lui répond. 





Undercapatalized small businesses 
20040626 

Greg pose la question : Suppose that 30% of all small businesses are undercapitalized. 40% of all
undercapitalized small businesses fail and 20% of all small businesses that
are not undercapitalized fail. A small business is chosen at random. The
probability that the small business succeeds if it is undercapitalized is? Greg
Penny Nom lui répond. 





Pick a number greater than 1 
20040625 

A student pose la question : I understand that when you pick a number greater than 1 and less than 10; multiply it by 7 and add 23, then add the digits of that number until you get a one digit number. Then multiply that number by 9, add the digits of that number until you get a one digit number, subtract 3 from that number and divide the difference by 3; that this process will always give you the result of 2. Does this have a name or theory for it as to why the answer will always be 2? Penny Nom lui répond. 





(a+b) + 5i = 9 + ai 
20040625 

Josh pose la question : The question which someone gave you (a+b) + 5i = 9 + ai question) gave me trouble. Penny Nom lui répond. 





(ln(50/x)) / (ln(40/x)) = a 
20040621 

Un eleve pose la question : (ln(50/x)) / (ln(40/x)) = a = constante
comment extraire la variable x ??? Claude Tardif lui répond. 





How much loam to fill a hole? 
20040619 

Harry pose la question : Can you tell me how much loam I would need to fill a hole 15 feet in dia. x 6 inches deep. Penny Nom lui répond. 





The surface area of a pyramid 
20040619 

Jason pose la question : I was wondering how to find the area of a pyramid when you donít know the height of the face but the height of the Pyramids highest point? Penny Nom lui répond. 





Forty balls are placed in a bag 
20040619 

Sheila pose la question : Forty balls numbered 110 are placed in a bag and four are drawn at random. What is the probability that the first ball drawn is between 110 (inclusive) the second is between 1120, the third is between 2130 and the last is between 3140? Penny Nom lui répond. 





3+4i abd 3+4i 
20040617 

Sandy pose la question : how would you do a question like 3+4i? is that different than just doing 3+4i? Penny Nom lui répond. 





An equation with rational terms 
20040617 

Louise pose la question : simplify the expression
(a^{2}+n^{2})/2n = a^{2} + (a^{2}n2)/2n Penny Nom lui répond. 





Area of a lot 
20040617 

Mike pose la question : Could you please figure out the square footage and acreage of my lot? One side is 228 feet, another is 150 feet, another is 80 feet, and the last side is 164 feet. My house is in the middle and it is 62 feet by 37 feet. Is that subtracted from the total? I would like to know this when I have to buy fertilizer.
Penny Nom lui répond. 





A garden space 
20040616 

Carol pose la question : We have a 17' x 19' garden space. If we want it a foot high raised bed, how many cubic yards of topsoil do we need? Penny Nom lui répond. 





The height of a building 
20040616 

Lauren pose la question : I have a homework assignment to measure a building on my school's campus. I have to stand at least 40 ft away from the building and find the angle of elevation from my feet to the top of the building. Then I have to walk at least 40 ft form that point, record the distance as X, and find the angle of elevation from my feet to the top of the building. Using X and the angles, I have to determine the height of the building. I used a protractor and a weighted string to find the angle of elevation from my eyes to the top of the building. But I haven't been able to find the way to measure the angle of elevation from my feet to the top. Penny Nom lui répond. 





Solving an equation 
20040614 

Anthony pose la question : I was hoping that you could help me with this problem. I believe that this is a high school level problem but as an adult who has forgotten the "rules", I am stuck.
the equation is this: x=t2/(t1t2)
we know that x=5.73
t1=303
we must solve for t2 Penny Nom lui répond. 





The Number of the Beast 
20040613 

A Heinlein reader pose la question : Most people who have an interest in mathmatics are familiar with Robert Heinlein's novel "The Number of the Beast", where 666, or ((6 to the 6th power) to the 6th power) equals 1.0315 times 10 to the 28th power, which in the novel is the number of parallel universes in the cosmos. My question is what would the number of parallel universes be if you grouped 666 the other way: (6 to the power of (6 to 6th power)). I have tried this on my calculator, but it won"t register that high. Penny Nom lui répond. 





Integers 
20040610 

A parent pose la question : I have an odd 3 digit product. My factors are a 1digit number and either or 2 or 3digit number. My factors are odd, but neither is 1. Find my factors and my product.
There is one answer. What is it? Penny Nom lui répond. 





Choosing an investment 
20040609 

Max pose la question : Let's say I have a list of different possible investements, and the list shows me my cost, and how much each investment will sell for.
In order to compare the investments and put them in order of relative profitability, I would want to sort them by their profits as percentages of what? Also, if each investment had an equal probability
of losing exactly 10% of the sell price before I sold would that have any relevance to the way I would calculate it? Walter Whiteley lui répond. 





Jack's social security number 
20040608 

A student pose la question : Jack's social security number contains each of the nonzero digits exactly once. By examining the digits from left to right, he also found that 1 divides the first digit evenly, 2 divides the sum of the first two digirs evenly, 3 divides the sum of the first three digits evenly, and so on, until 9 divides the sum of all the digits evenly. What is Jack's social security number? Penny Nom lui répond. 





The sum of some positive integers 
20040607 

A student pose la question : Find the sum of all positive integers not greater than 10000 that are divisible by neither 3 nor 7. Penny Nom lui répond. 





What is the name of a 3D rectangle? 
20040607 

Jack pose la question : if a cube is a 3D square, what is the name of a 3D rectangle? Penny Nom lui répond. 





The area of a pentagon 
20040606 

Dana pose la question : HELLO, I NEED HELP IN DETERMINING THE SIZE OF A PENTAGON.
one side is 280',from both ends of the 280 'section,we have 300' lengths,from one of these 300' sections we have a 118' length,which goes over to a length of 228',will this be enough info. or should i provide more. thanks Penny Nom lui répond. 





Percentage markup 
20040604 

A parent pose la question : if our cost is 54.00 and their cost is 117.00 what is the percentage of mark up? Penny Nom lui répond. 





A tangent to a quadratic 
20040604 

Jem pose la question : I have a question on the tangent to a quadratic curve.
Say I have a curve y = ax^{2} + 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 yaxis where the tangent cuts isn't it? Is there a formula for it? Penny Nom lui répond. 





The game of 24 
20040604 

Samantha pose la question : i have the game 24 (the one where you have to use multiplication, division, addition, and subtraction to get to the answer 24) I was playing when i came across the 4 numbers 20, 17, 7, 11 and i cant seem to get 24. Claude Tardif lui répond. 





Divisors of 2n+1 and 3n+9 
20040602 

Chris pose la question : Amy selected a positive integer N and wrote numbers 2xN+1 and 3xN+9 on a whiteboard. Boris looked at the two numbers on the whiteboard and wrote in his notebook a positive integer that divides each of them. Find all possible numbers that Boris could have written in his notebook. Chris Fisher and Penny Nom lui répond. 





Cubic yards in a pool 
20040530 

Jerry pose la question : HAVE A AREA WHERE I HAD A 18 FOOT ROUND POOL.
THE DEEPEST PART IT WAS IN THE GROUND WAS AROUND 7 INCHES TAPERING DOWN TO AROUND 4 TO FIVE INCHES AND A LITTLE OF THE ONE SIDE ALMOST AT GROUND LEVEL...HOW MANY YARDS OF DIRT WOULD I NEED TO FILL IT IN???? IS THERE A FORMULA FOR THAT.......COULD YOU FIGURE THAT FOR ME?
Penny Mon lui répond. 





The Parliament of the land of Achronia 
20040529 

Christine pose la question : The Parliament of the land of Achronia consists of two houses. The parliament was elected in 2003 for a period of six years beginning on Thursday, the 1st of January 2004, when the two houses had their first sessions. According to the rules, the meetings of the first house must occur every twelve days for the duration of the term, and the meetings of the second house must occur every eighteen days. For example, the second meetings of the first and the second houses were held on the 13th and 19th of January respectively. A new law can be passed on any day when both houses meet, except on a Thursday. On how many days can the parliament members pass new laws during this six year term? Penny Nom lui répond. 





112! 
20040528 

Beatriz pose la question : 1) A bus driver collects identical sets of 5 coins from each passenger. If the totoal colledted was $21.83, how many pennies did the driver get??
2) How many terminal zero in the base 10 expression of 112! (factional) N! means N(N1)(N2) .....(2) (1). Penny Nom lui répond. 





Different infinities 
20040527 

Plober pose la question : How can I explain to a friend (in a bar, using as a pen and a paper napkin) that the integer's infinity is 'smaller' than the irrationals's one? The demo I tried was that you couldn't match the integers with the real numbers between 0 and 1 (that 0.xxxxx replacing the Nth number from a different one... that demo), but she used my argument >: saying that you can add one to the integer's infinite, and the number I was creating was only one more...
I can't think of any other way, and I KNOW the real's cardinality is greater than the integer's one Claude Tardif and Penny Nom lui répond. 





English 
20040527 

Chang pose la question : well my question is i was told by most of the teachers that ''think in english'' is the best way to learn english but how can i do like that do i need to know about the stucture first or do i need to learn the western culture ?
here is a sentence i have translate directly from my mother language.'' i was given an admiration of sincerity from this client on the follow up action i have done in the complaint. Claude Tardif lui répond. 





The horizontal fraction bar 
20040527 

Kashia pose la question : What is the name of the bar that separates a numerator and that denominator? Penny Nom lui répond. 





The center of a circle 
20040526 

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. 





The base of a triangle 
20040525 

Ralph pose la question : With a 30 degree angle at the top of a triangle and a height of 15 what is the base? Penny Nom lui répond. 





Programming without trig functions 
20040525 

Derek pose la question : I am a programmer trying to calculate the following.
What is the formula to find the crosssectional area of a cylinder with out using any trig functions? or better yet, how can you calculate any given volume in a cylindrical tank with spherical heads with out trig functions?
I am using a PLC (programmable logic controller) to do this and trig functions are not available. Harley Weston lui répond. 





Finding bearings 
20040524 

James pose la question : This question is about finding bearings. A boat race starts from point A, goes North to Point B, a distance of 1000 meters. The course is triangular. The bearing from point B to point C is South 70degrees West. The distance from Point B to point C is 1500 meters. Find the course bearing from C to A.
Penny Nom lui répond. 





Some trig expressions 
20040523 

A student pose la question : Prove:
sin A + sin B = 2sin(A+B/2)cos(AB/2)
cos A  cos B = 2sin(A+B/2)sin(AB/2)
cos A + cos B = 2cos(A+B/2)cos(AB/2)
sin A  sin B = 2cos(A+B/2)sin(A+B/2) Penny Nom lui répond. 





Volume of a box 
20040523 

A student pose la question : The area of the top of a closed rectangular box is 252cm2, the area of the front of the box is 105cm2, and the surface of the box is 834in2 (or 5380.64cm2). What is the volume of the box? Penny Nom lui répond. 





How far apart are they? 
20040523 

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. 





33 3/4 doubled 
20040522 

A tailor pose la question : need to know how to add 33 3/4 doubled. How do I come up with the solution? I need to know for measuring garments. Usually I measure on the half meaning on the front of the garment and then double it with the measuring tape but I always get stuck when I need to measure 3/4 such as 66 3/4 doubled and etc. Can you help me figure this out easily. Penny Nom lui répond. 





The perimeter of a triangle 
20040521 

A student pose la question : In a triangle i have the length of a line and it's opposite angle.how can i calculate perimeter?(the angles are not right) Penny Nom lui répond. 





Frieze patterns 
20040519 

Christina pose la question : How can I prove that there are only seven unique geometric frieze patterns? Penny Nom lui répond. 





Word problems 
20040519 

A student pose la question : why can't 2nd graders have a easy time doing word problems and drawing pictures with it
Diane Hanson lui répond. 





The dimsenions of a room 
20040518 

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. 





Angles of elevation and depression 
20040518 

Anjum pose la question : what is the difference between an angle of elevation and angle of depression? Penny Nom lui répond. 





The combinatiion for a keybox 
20040517 

Darrin pose la question : I have a puzzle question based on reality. I have a realestate type keybox (Supra) that has 10 digits, 09. I am trying to figure out a methodical way to test all number combinations to it to open it. (totally legal it was taken from the trash at a jobsite since they couldn't open it!) The combination could be any or all of the digits, but any digit is only used once. This is not like a simplex lock problem where a combination of keypresses would be different i.e. 1,2,3 is the same as 1+2,3.
Any ideas? Penny Nom lui répond. 





Diagonals in a regular dodecahedron 
20040515 

Joshua pose la question : A dodecahedron has twelve faces, all of which are regular pentagons. Three edges meet at each vertex of the dodecahedron. An interior diagonal is a segment connecting two vertices such that the segment is not an edge or along a face of the dodecagedron. How many interior diagonals does a regular dodecahedron have? Penny Nom lui répond. 





Maximizing the angle to the goal mouth 
20040515 

Yogendra pose la question : You are running down the boundary line dribbling the ball in soccer or hockey. Investigate where in your run the angle the goal mouth makes with your position is at a maximum. Penny Nom lui répond. 





Mrs. Smith's class 
20040512 

Amanda pose la question : Mrs. Smith's class has 35 student. Today there are 2/3 of them absent. How many are absent? present? Penny Nom lui répond. 





Subtracting fractions 
20040511 

Filipe pose la question : Question:
_5_  __7__
6ab 8a Penny Nom lui répond. 





Area of a lot 
20040511 

Dana pose la question : HELLO MY NAME IS DANA ,I AM AN AVERAGE JOE WITH A QUESTION THAT I CANNOT ANSWER MYSELF SO I CAME TO YOU, I HAVE A PIECE OF PROPERTY IN THE SHAPE OF AN ISOSCELES TRAPEZOID THAT IS 250 FEET ACROSS THE BACK, 100 FEET ACROSS THE FRONT AND BOTH SIDES ARE 600 FEET LONG. HOW MANY SQUARE FEET ARE IN THIS PROPERTY.?
Penny Nom lui répond. 





A pyramid 
20040511 

Quiana pose la question : I am a student and I have the following questions I need to answer for homework:
How many sides, vertices, and edges does a pyramid have? Penny Nom lui répond. 





Three dice 
20040510 

A student pose la question : If one has 3, 6 sided dice what is the probability of the numbers that are rolled to total 4 through 10 inclusively?
Subsequent to this, what is the probability to do this consecutively...say 3 times? Peny Nom lui répond. 





Pi 
20040510 

Kim pose la question : I'm a 7th grader at Lakeside Middle School. And I was wondering if you can answer a question for me for my math project. I'm doing a project on pi, and my teacher said to ask an expert like you to ask about how you would use the subject, pi, in real life usage. How would you use pi in real life usage? Penny Nom lui répond. 





Why the word combinations? 
20040505 

Megan pose la question : Why are locker combinations called locker combinations not locker permutations. The order of the numbers matter so why aren't they called locker permutations. Claude Tardif and Penny Nom lui répond. 





ChiSquared 
20040505 

Gillian pose la question : OF75 PEOPLE, 43 ARE EXPOSED TO A VIRUS AND BECOME ILL. 11 PEOPLE ARE EXPOSED AND DO NOT BECOME ILL. 3 PEOPLE ARE NOT EXPOSED AND BECOME ILL. 18 PEOPLE ARE NOT EXPOSED AND DO NOT BECOME ILL. THE ATTACK RATE IS 80% FOR THOSE EXPOSED AND 14% FOR THOSE NOT EXPOSED. THE RELATIVE RISK IS 5.7. CAN YOU EXPLAIN TO ME HOW TO CALCULATE A CHI SQUARE TEST FROM THIS. Penny Nom lui répond. 





3x squared  27 / x + 3 
20040504 

Stef pose la question : 3x squared  27 / x + 3 Penny Nom lui répond. 





A 3 digit number divisible by 7 
20040503 

A student pose la question : We need to arrange 1,3 and 6 to form a 3 digit number that is divisible by 7. Penny Nom lui répond. 





Solving inequalities 
20040503 

Joe pose la question : Let x be a real number find and graph the solution to the following sentances:
2x10+9
4X+2<15
5X+3>(x1) Peny Nom lui répond. 





A clock chimes 7 times in 7seconds 
20040502 

Anna pose la question : A clock chimes 7 times in 7seconds. how long does it take the clock to chime 10 times? Penny Nom lui répond. 





The equation of a line 
20040430 

Amy pose la question : Write the equation of the line that contains the point (4,6) and is perpendicular to the line y=5x+100. Penny Nom lui répond. 





Setting up an equation 
20040430 

Matt pose la question : I am trying to determine the dimensions of a 22 megapixel digital camera chip that has a 3:2 ratio. We know then, that: 3x = 2y (or 1.5x = y)
and that
xy = 22
Beyond this, I don't know how to hook those 2 seemingly unrelated facts together. Penny Nom lui répond. 





The sum of 4,0,4..., 156 
20040428 

Christina pose la question : find the requested sum of the arithmetic sequence
4,0,4..., 156 Penny Nom lui répond. 





Yards in a concrete driveway 
20040427 

Bobbi pose la question : I am wondering how many yards of cement I need for a 49 by 45 area, 5 inches thick. I am a stay at home mom who is not very good at math and I want to pave my drive way. Also what would the yardage be for a 6 inch thick drive way with the same area. Penny Nom lui répond. 





Factoring 
20040427 

Bipin pose la question : FACTORISE:
a to the power of 6 + b to the power of 6 Penny Nom lui répond. 





An oildrilling platform 
20040427 

Alie pose la question : An oildrilling platform is located in the Gulf of Mexico 3.25 miles from the nearest point on shore. From a point B on the shore due east of A the bearing of the platform is S51.2W. How far is it from B to the platform? Penny Nom lui répond. 





The height of a triangle 
20040427 

Danielle pose la question : what is the definition of height of a triangle? Penny Nom lui répond. 





Related rates and baseball 
20040426 

Bethany pose la question : A baseball diamond is the shape of a square with sides 90 feet long. A player running from second to third base at a speed of 28 feet/ second is 30 feet from second base. At what rate is the player's distance from home plate changing? Penny Nom lui répond. 





The problem of Apollonius 
20040425 

Mitja pose la question : There are given 2 circles lying one out of another and one point out of both circles. How to construct a circle passing through a given point and internally tangent to one and externally tangent to the other cirlce? Chris Fisher lui répond. 





A Fibonacci triangle 
20040425 

Marcelle pose la question : Is it possible to construct a triangle with sides that are three consecutive Fibonacci numbers? Walter Whiteley lui répond. 





Water in a pipe 
20040425 

Marlean pose la question : How much water would be in a 480 foot one inch inside diameter pipe?? In imperial gallons please. thanking you in advance for your help in this matter.
Penny Nom lui répond. 





Place Value 
20040425 

Santosh pose la question : Q.
Write the Place value of the digits in the following numerals.
1. 5 in 54
2. 3 in 63 Penny Nom lui répond. 





Marching legion 
20040424 

Art pose la question : A column of soldiers is 100 meters long. Their sargeant at the rear of the column gives the order to march. The sargeant marches alongside the column to its head and then back to the rear, at which point he gives the order to halt. In all, the column of soldiers has marched 100 meters. How far has the sargeant marched? I say 187.5 meters, but those who teach or who have taught mathematics tell me no. Some say much more and some different. What do you say? Penny Nom lui répond. 





Three parabolas 
20040424 

A tutor pose la question :
I am a maths tutor. One of my year 12 students has given me this assignment. Many parts are ambiguous.
I am trying to determine the equation of the line segment AB. Given that A has an incline of 10 degrees below the horizontal, I am assuming that this parabola (although you can only see part of it) has been rotated 10 degree clockwise. Am I right in assuming this? If so, how do I derive the equation of the parabola as it will then not fit the general form y = ax squared +bx +c of a parabola.
Also, how is one expected to find the x coordinate of D without the equation of this parabola. To find the equation you need the xcoordinate and therefore be able to find another point on the parabola in order to derive the equation using simultaneous equations.
Penny Nom lui répond. 





Arrays 
20040423 

Jan pose la question : 4x7 = 28
How many arrays can this have? How do you determine the arrays??? Penny Nom lui répond. 





square root 125 x 16 
20040423 

Mike pose la question : how do you simplify a square root of " square root 125 x16" when x is a variable... i don't really get how to do this.... Penny Nom lui répond. 





The "22" puzzle and the "1089" puzzle 
20040422 

Marcelle pose la question :
1. Choose 3 digits from 19
2. Make all the 2 digit numbers you can from these (6)
3. Add the 3 original digits and divide them into the sum from step 2.
The answer is always '22'. I just can't understand why. Can you please help.
Another one related to this is it:
1. Choose a three digit number ensuring the first and third digit are differnt by at least two.
2. Make the reverse three digit number and subtract the smaller one from the larger of these.
3. Take this answer and reverse it and add these two 3 digit numbers .
eg:
643  346 = 297
297 + 792 = 1089
it doesn't matter what numbers are used, the results are alwasy the same. eg 22 or 1089
Paul Betts lui répond. 





Why is ounces abbreviated oz? 
20040422 

Someone curious pose la question : Why is ounces abbreviated oz? Chris Fisher lui répond. 





What's it called? 
20040422 

Gerry pose la question :
I'm a father and a grandfather and have come up with a game for my offspring to play while we're on the road. When we see a license plate, the object is to be the first one to add all the numbers on it, and come up with THE one digit number that sums them up.
For example: ABC787 = 7+8+7 = 22 = 2+2 = 4
Another example is 2932 = 2+9+3+2 = 16 = 1+6 = 7
Up 'til now, I've called it just plain "Numerology", but I'm sure that there's a math term for what we're doing, and I'd sure appreciate it if you could tell me what it is!
Chris Fisher and Penny Nom lui répond. 





Surface area of a cylinder 
20040417 

Kathryn pose la question : How do you find the radius of a cylinder when you are given only the surface area and the height of the cylinder? Penny Nom lui répond. 





The line through (4,2) and (4,8) 
20040417 

Kim pose la question : Write an equation for the line.
Given points (4, 8) and (4,2) are on the line.
I believe m=undefined.
How do I solve for b when m is undefined, and then plug in the values for m, b, and y?
Penny Nom lui répond. 





Some factoring problems 
20040415 

KJ pose la question : Factor these:
x^{3}+125 > (x+5)^{3}
8x^{3}27 > (?)
x^{2}+36 > (x+6)^{2}
x^{4}5x^{2}+4 > (?) Penny Nom lui répond. 





A probability density function 
20040414 

A student pose la question : The label on a bottle of liquid detergent shows contents to be 12 ounces per bottle. The production operation fills the bottle uniformly according to the following probability density function:
f(x) = 8 for 11.975 <= x <= 12.10
and
f(x) = 0 elsewhere
a. What is the probability that a bottle will be filled with 12.02 or more ounces?
b. What is the probability that a bottle will be filled between 12 and 12.05 ounces?
c. Quality control accepts production that is within .002 ounces of number of ounces shown on the container label. What is the probability that a bottle of this liquid detergent will fail to meet the quality control standard? Penny Nom lui répond. 





A geometric sequence 
20040413 

Michael pose la question : In a geometric series, the sum of the 2nd and 3rd terms is 60, and the sum of the 3rd and 4th terms is 240. Find the sum of the first 7 terms. Penny Nom lui répond. 





Circles in a hexagon 
20040411 

Crystal pose la question : step by step can you show me how to calculate the area of the region inside the hexagon but outside the seven circles. given the radius of each circle is one inch Penny Nom lui répond. 





Percent difference 
20040410 

A parent pose la question : For a school science project, my son Alex is taking measurements of plant growth at regular intervals. As part of the data, he must provide the maximum percent difference observed in the categories his team has identified.
So, for example he has six plants with four measurements each. (He has more, but I'll keep it simple) For the first plant he measured 2mm, 2.4mm, 2.9mm, and 3.2mm. For the 2nd, 3rd, and 4th plants, he has similar numbers. Is there a way to calculate the maximum percent difference between any two plants in his measurements during the project? Doing it for each combination would be tedious. Penny Nom lui répond. 





Snow in the driveway 
20040409 

Patricia pose la question : Following a severe snowstorm, Ken and Bettina Reeves must clear their driveway and sidewalk. Ken can clear the snow by himself in 4 hours, and Bettina can clear the snow by herself in 6 hours. After Bettina has been working for 3 hours, Ken is able to join her. How much longer will it take them working together to remove the rest of the snow? Penny Nom lui répond. 





What is the nth term 
20040407 

Jason pose la question : 1 4 10 20 35 56 84
what is the nth term Claude Tardif lui répond. 





Rational expressions 
20040406 

Shivani pose la question : I am in 11th grade Honors Algebra II. We are currently learning about adding and subtracting rational expressions. I looked at the other questions that were similar to that of mine, but they weren't quite answering my question. I have been working on many problems to practice and see if I can come up with the correct answer, but I can't, I got like 2 out of every 7 right on my school homework. I get the easy ones, where when you have to find the LCD, it's just the other denominator. But, on others you have to really think about it. Those are hard. Here are some of the problems that I cannot get at all: (x2  3x + 1)/(x2  4)  (x2 + 2x +4)/(2  x)  (x  4) /(x  2)
The correct answer is:
(x3 + 4x2 + 7x + 17)/(x2  4) Penny Nom lui répond. 





The sum of angles in a triangle 
20040406 

A student pose la question : How can u prove sum of angles in a triangle equal to 180 degrees? Penny Nom lui répond. 





Differences in percentages 
20040406 

Jose pose la question :
Question:
You have two groups:
Group A has 10 people and 2 are Chinese
Group B has 12 people and 3 are Chinese
In terms of percentages what is the difference in Chinese between the two groups? In other words which group has the biggest percentage of Chinese and why?
Penny Nom lui répond. 





Trisecting an arbitrary angle 
20040406 

Joe pose la question : Where can I submit my effort on trisecting an arbitrary angle with only a straightedge and a compass? I can do it but I do not have the smarts to prove it.S Chris Fisher lui répond. 





Ratios 
20040405 

Tim pose la question : The ratio of W to H was 7 to 9. The ratio of H to I was 9 to 5. If the sum of the W and H exceeded twice the number of I by 12, how many were W, how were H and how many were I? Penny Nom lui répond. 





x^2/3  7 x^1/3 + 12 = 0 
20040405 

Jackie pose la question : I am having trouble solving this question for x:
1.) x^2/3  7 x^1/3 + 12 = 0 Penny Nom lui répond. 





(3x50)+20/5=? 
20040403 

A student pose la question : what is the answer to:
(3x50)+20/5=? Penny Nom lui répond. 





A changing rectangle 
20040403 

A student pose la question : The width x of a rectangle is decreasing at 3 cm/s,
and its length y is increasing at 5 cm/s. At what rate
is its area A changing when x=10 and y=15? Penny Nom lui répond. 





Ratio and proportion 
20040402 

Kenneth pose la question : The terms of a ratio in a proportion are often expressed as a is to b as c is to d.
Example: 2/4 = 6/12 this proportion represents that 2 is to 4 as 6 is to 12.
What does the "a is to b as c is to d" really represent or indicate in ratios? Claude Tardif lui répond. 





Some calculus problems 
20040401 

Weisu pose la question :
I have questions about three word problems and one
regular problem, all dealing with derivatives.
 Find all points on xy=e^{xy} where the tangent line
is horizontal.
 The width x of a rectangle is decreasing at 3 cm/s,
and its length y is increasing at 5 cm/s. At what rate
is its area A changing when x=10 and y=15?
 A car and a truck leave the same intersection, the
truck heading north at 60 mph and the car heading west
at 55 mph. At what rate is the distance between the
car and the truck changing when the car and the truck
are 30 miles and 40 miles from the intersection,
respectively?
 The production P of a company satisfies the
equation P=x^{2} + 0.1xy + y^{2}, where x and y are
the inputs. At a certain period x=10 units and y=8
units. Estimate the change in y that should be made to
set up a decrease of 0.5 in the input x so that the
production remains the same.
If you could just give me some hints on these
questions, I'd really appreciate it. Thanks! Penny Nom lui répond. 





The intersection of two graphs 
20040331 

Benjanim pose la question : How do I find the points of intersection of the two functions:
1) y = 2  (e^x)
2) y = 1 + (x^2)
I know that I have to set them equal to each other, but I can't solve for x. Please help :) Penny Nom lui répond. 





Algebraic simplification 
20040331 

Chris pose la question : Simplifying Exponents
Question
b^5d^2/b^3d^8 Penny Nom lui répond. 





The degree sequence of a graph 
20040331 

Ali pose la question : How can i find out {6,6,5,5,5,3,2}is not the sequence of the points of a simple graph,without drawing it? Penny Nom lui répond. 





Replacement times for TV sets? 
20040331 

Barb pose la question : Replacement times for TV sets are normally distributed with a mean of 8.2 years and a standard deviation of 1.1 years. Estimate the probability that for 250 randomly selected TV sets, at least 15 of them have replacement times greater than 10.0 years.e Andrei Volodin and Penny Nom lui répond. 





A derivative 
20040331 

A student pose la question : What is the nth derivative of f(x) =(2x)/(1(x^{2}))? Harley Weston lui répond. 





The height of a building 
20040331 

Nat pose la question : Two buildings are 26.3m apart. From the top of the shorter building the angle of elevation to the top of the taller building is 35.9 degrees and the angle of depression to the base of the taller building is 54.7 degrees. What is the height of the taller building? Penny Nom lui répond. 





425 cc's of a saline solution 
20040330 

Julie pose la question : 425 cc's of a saline solution is equal to how much in lbsweight?? Harley Weston lui répond. 





n! > n^2 
20040330 

Jose pose la question : How can you prove by mathematical induction that:
n! > n2. Penny Nom lui répond. 





A stained glass window 
20040329 

Kay pose la question : I'm doing a stain glass project and it's on a 4 foot across octagonal window...and I'm trying to set up the pattern and I don't know how long the sides are! Penny Nom lui répond. 





Numbers around a circle 
20040328 

Rebecca pose la question : my maths question is use the numbers 1,2,3,4,5,6 and 7 place each number in a circle so each line adds up to 12. There are seven circles, six on the outside and one in the middle. Each number lines up with the middle number and the outside numbers line up with the one directly across from it as if a line was going through the middle number circle. Penny Nom lui répond. 





Percentage difference 
20040328 

Someone pose la question : what is the percentage difference between 157 to 251 Penny Nom lui répond. 





Maximizing the area 
20040327 

Petey pose la question : Please could you tell me why for my coursework (where I have to find the largest area that a fence 1000m long can cover) why I should only test equilateral and isoceles triangles? We were told NOT to do right angled triangles but I was wondering why not?
Penny Nom lui répond. 





The volume of a sphere 
20040326 

Mike pose la question : I was in class today and I learned how to calculate the volume of a sphere. I understood it easily but can't find the logic behind it. So here are my questions, in the formula why is the radius cubic and not squared? And what does 4/3 have to do with it? Penny Nom lui répond. 





z^2 = 3  4i 
20040326 

John pose la question : Solve: Z^2 = 3  4i Harley Weston lui répond. 





Large exponents 
20040326 

John pose la question : I
have encountered problem with the lack of memory every calculator
seems to have. No calculator, on or off the computer, I've found
has the amount of memory or writing space to calculate the sums I want
to solve. The sums are in great importance for my continued progress.
The sums are following:
16777216^1310270, 16777215^995328, 16777215^786432 and 16777215^480000 Claude Tardif lui répond. 





Sections, area and acres 
20040323 

Tony pose la question : An acre , it can be any size right . so when they
refer to a section of a township which is 640 acres,
also 1 square mile does this mean that 1 sections
length if sqaure and there is 5,280 ft in 1 mile does
it meanthat if you took 1 side of the square of of 4 sides
the lenth would be 5,280 feet long and by multiplying
5,280 x 5,280 it would give you the square mile in
square feet. i guess what I 'm asking is what is the
perimeter of 1 acre if it was shape like a square.
sorry to make this confusing but if you can help I
would appreciate it. Penny Nom lui répond. 





Four marbles on a box 
20040322 

Karyn pose la question : Suppose 2 solid color marbles and 2 striped marbles are placed in a box. All are the same size. If one marble is randomly drawn from the box and replaced, then a second marble is randomly drawn, what is the probability that the marble drawn both times will be striped?
I know there is a simple formula for working this out but I can't remember how.
Penny Nom lui répond. 





What's the next term? 
20040322 

Garrett pose la question :
A friend hit me with these questions and won't tell me the answer nor how... please help? I've racked my brain and did all sorts of formulas, but I can't get it to work out... please...
What's the next number in this series...
5, 12, 17, 29, 46, ?
And this series...
12, 19, 28, 39, 52, 67, ?
and these...
ocoa, boco, oboc, dobo, odob, ?
Claude Tardif lui répond. 





BEDMAS 
20040320 

Brad pose la question : I am in grade 7. My teacher tells me brackets always first, well i know that but, 5 (4) x 2
Does the (4) count as a bracket or is it just telling you not to minus 4 from 5 but to multiply 5 x 4 ? Am i correct? Penny Nom lui répond. 





A partial derivative 
20040319 

Penny Nom pose la question : Is it possible to differentiate the following equation, if so could
you please explain.
S=SQRT(T(5/X^2))
I would like the derivative of S with respect to X. Harley Weston lui répond. 





A fraction of a fraction as a percent 
20040318 

Mary pose la question : I would like to know if you could help me with this problem? Could you
take me though the steps
to this math problems.
3 =(?)% x 3
 
16 4
the question states: Finding what is the percentage of a fractional
number and another fractional number. Penny Nom lui répond. 





A water lily 
20040317 

Inba pose la question : A water lily with a rigid stem extends one foot above the surface of the water. When pulled over, it disappears beneath the water at a distance 3 feet from where the stem originally entered the water. How deep is the pond? Penny Nom lui répond. 





Factoring x^2 + 5x + 4 
20040314 

Keenan pose la question : how do I factor x^+5X+4? Penny Nom lui répond. 





Johann Muller 
20040314 

A student pose la question : What major contributions to spherical trigonometry did Johann Muller make? Penny Nom lui répond. 





Baseball games 
20040314 

Fabian pose la question : Let's say I have 12 different Baseball games. There is one of only 2 possible outcomes for each of the 12 games. How would I fugure out how many combinations there are for the 12 games and for 11,10, and so fourth.
Penny Nom lui répond. 





A new baby 
20040314 

Jessica pose la question : I just had a baby 3weeks ago, he is in the hospital and he can come home when he is 1800 grams, well i was wondering how many pounds that is? Penny Nom lui répond. 





Some ratio problems 
20040313 

Hossen pose la question :
1) After James spent 2/5 of his pocket money on magazines, and 1/4 of his pocket money at a football match, he had £1.75 left. How much pcket money did he have in the beginning?
2) A joint of Lamb costs £5.95 per/kg. The price per kilogram is reduced. A joint weighing 1.2kg is reduced by 50p.
A) What is the reduced price per kilogram?
c Penny Nom lui répond. 





Billions in Australia 
20040312 

An Australian pose la question : how many million in one billion ? Penny Nom lui répond. 





Area and perimeter 
20040312 

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 x1. Penny Nom lui répond. 





Sum of the angles in a pentagon 
20040311 

Ashish pose la question : What is the sum of all the measures of the angles of a Pentagon Penny Nom lui répond. 





Distance, time and rate 
20040309 

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. 





The area of a lot 
20040309 

Dave pose la question :
If our lot is 192.71 x 138.79 x 158.74 x 103.08
Question is what percentage of an acre is our lot?
Penny Nom lui répond. 





The factor theorem 
20040308 

LisaMarie pose la question :
Hi, I have a career link question from gr.12 advanced functions
and intro. calculus. The equations is:
R(t) = 5(t^{4}  4t^{3} +
19/4 t^{2}  3/2 t)
The question is to apply the factor theorem
and quadratic formula to determine the times it crosses the t axis. The
only method i know of for using the factor theorem is when the last number
does not have a variable beside it so i'm not sure how you would even
use the factor theorem for this? We haven't dealt with any that have 0 as
the last number with no variable so i'm a little confused! please help!
Thank you
Penny Nom lui répond. 





A metric prefix table 
20040307 

April pose la question : Can you tell me what the scale is for nano, micro, mega, kilo, etc.... I know that mega is 10 to the sixth power but I can't remember the other ones. Penny Nom lui répond. 





Equivalent sets 
20040306 

A student pose la question : If A=(1,2,3,4,...) and B=(5,10,15,20,...), is A equivalent to B. Why or Why not ? Penny Nom lui répond. 





The radius of a circle 
20040306 

A student pose la question : what is the radius of a circle with the circumference of 12 inches? Penny Nom lui répond. 





The units digit of 4^478 
20040306 

Elizabeth pose la question : What is the units digit of 4^{478}? Penny Nom lui répond. 





A fifteen sided polygon 
20040305 

Joann pose la question : WHAT IS THE NAME OF A FIFTEEN SIDED SHAPE? Penny Nom lui répond. 





A geometry problem 
20040304 

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. 





Cosine of 35 degrees 
20040303 

Jason pose la question : How do you find the exact solution to cosine 35 degrees. Chris Fisher lui répond. 





Proof by induction 
20040302 

Chris pose la question : I need some help of how to solve the problem
"use the principle of mathematical induction to prove that the following are true for all positive integers"
cos(n x pi + X) = (1)^n cosX
any help would be appreciated Penny Nom lui répond. 





Volume of a fuel tank 
20040301 

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. 





Billions and more! and even more! 
20040301 

Steph pose la question : What comes after undecillion? Penny Nom lui répond. 





Evennumbered roots 
20040301 

A student pose la question : I understand that the square root is defined to be positive only. Does
the same rule apply to other evennumbered roots, such as the 4th root, or
the 6th root, etc.? Harley Weston lui répond. 





Logs 
20040229 

Sandy pose la question : find X
3/2logb41/2logb8+logb2=logbx
my book uses prop 7 to rewrite as
logb4raised3/2logb8raised2/3+logb2=logbx; then writes
logb8logb4+logb2=logbx how did it get here? Claude Tardif lui répond. 





A dressmaker's pattern 
20040227 

A dressmaker pose la question : Does a dressmaker's pattern for a dress, such as a skirt made up of several pieces of isosceles trapezoid, qualify as a net? How about patterns for other types of clothing or accessories e.g. jackets, handbags?Î Diane Hanson lui répond. 





Napoleon's theorem 
20040227 

David pose la question : How do i prove this : For any triangle, if you make 3 equillateral triangles
using the sides of the the original triangle, the central points of the 3
tringles another triangle that is equillateral.z Chris Fisher and Penny Nom lui répond. 





GST and PST 
20040226 

Mallory pose la question : I was absent on the day that my teacher taught the class how to find the GST and PST of items. I sort of understand that GST is 7% and PST is 7.5%, but our teacher said that we shouldn't combine the two to find the total amount... I'm really confused, so can you please help me?& Claude Tardif lui répond. 





Three jugs 
20040226 

Shelly pose la question : You have three jugs: A 6 Liter, 4 Liter and a 3 Liter. Your goal is to get exactly 5 Liters of liquid in the 6 Liter jug. Your supply of liquid is unlimited and there are NO markings on the containers. You cannot do halves. Claude Tardif lui répond. 





The point where all the medians meet 
20040225 

A student pose la question : What's the name of the point where all the medians meet? Penny Nom lui répond. 





Rearranging an expression 
20040224 

Corey pose la question :
use the following formula to answer the question
F=9c divided by 5 plus 32
rearange the formula to solve for c
how many degrees fahrenheit would it be it it was:
0 degrees celcius
10 degrees celcius
46 degrees celcius
Penny Nom lui répond. 





An elliptic cone 
20040224 

Ben pose la question :
I am building a model for my architecture class. I need to build a elliptic cone out of chipboard and i have no idea how to do this.
The cone needs to be 20in tall and the ellipse has a max radius of 10in and a min radius of 8in.
So my question is how do i lay this out on a piece of paper so that i can form the cone after i cut it out.
Penny Nom lui répond. 





Profit, markup and discount 
20040222 

Kick pose la question : Using the calculation on your website, if I sell something for $885 and my cost is $296, I make $589 profit. How do I calculate the profit percent I made on that transaction?
Profit as a percentage of what it cost me?
Profit as a percentage of what I sold it for?
Penny Nom lui répond. 





A problem with logs 
20040222 

Caitlyn pose la question : problem: ln x + ln (x2) = 1
I can solve this on the calculator, but the book wants 1+ [(sqroot)1+e]. How can I get the e? Penny Nom lui répond. 





Selecting balls from a golf bag 
20040221 

A student pose la question : There are 5 white and 5 yellow balls in a golf bag. Two are selected randomly, and simultaneously. What is the probability that the first one or the second one will be white? Penny Nom lui répond. 





The dimensions of a rectangle 
20040221 

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. 





Gallons in a cylinder 
20040220 

Jim pose la question : Please advise how to use the formula I saw for determining the number of gallons in a cylinder? This is how it was written
V = pi r2 h
. does this mean pie, or 3.14 X radius squared, X the height? If so please use a standard 55 gal barrel (1' R & 3' H) for example? Penny Nom lui répond. 





Arrays 
20040219 

A parent pose la question : please demonstrate mathematical arrays fro a 3rd grader Penny Nom lui répond. 





A worm crawling home 
20040218 

Cindy pose la question : A worm is crawling to his home which is one meter away. The longer he crawls the weaker he gets and the less he can crawl the next day. If he crawls within 1/3000 of a meter of his home, he will find food. He must eat within twelve days. The first day he crawls 1/2 meter. The second day he crawls 1/4 meter. The third day he crawls 1/8 of meter. This pattern continues for twelve days. Make a Chart that shows the distance he has covered at the end of each day and the total he has covered at the end of each day. Does he make it to the Food in time? Penny Nom lui répond. 





Nonconvex shapes 
20040218 

Merrill pose la question : Draw 4, 6 and 8 sided shapes so that ONE straight line can be drawn through each side Chris Fisher and Penny Nom lui répond. 





Acres and square miles 
20040217 

Richard pose la question :
How many acres are in .17 square miles? and How many acres are in .6 square miles?
The two areas I am requesting information about are Vatican City and San Marino, the two smallest countries in the world. If I can transfer the sq. miles into acres , I can relate the size of these countries to our school grounds and the students will better understand their sizes.
Penny Nom lui répond. 





Grams and Milliliters 
20040217 

Chantal pose la question : We have to do a "thing", and I need to convert grams into mililitres (g into mL). how can I do this? Penny Nom lui répond. 





Areas, perimeters and derivatives 
20040215 

Geoff pose la question : A recent lecture in my calculus class led me to realize that the derivative of the area of a circle, with respect to the radius is equal to the circumfrence. This also holds true for the relationship between the volume of a sphere and the surface area of that sphere:
why do these hold true? why is it only for circular objects? Harley Weston lui répond. 





An arc on a train track 
20040215 

A student pose la question : I'm trying to build a route in a train simulator program. I have a curve to the right (an arc, in other words) with a length of 25 meters and the radius is 1,500 meters. Let's say point P is the beginning of the curve (arc) and point Q is the end point of the arc. Then picture a tangent to point P. I need to find the length of a line perpendicular to that tangent that runs to point Q (the end of the curve/arc). Penny Nom lui répond. 





The derivative of x to the x 
20040214 

Cher pose la question : what about the derivative of x to the power x? Penny Nom lui répond. 





The substitution method 
20040214 

Keisha pose la question : I need to solve this problem by using the substitution method.
3x+y=1
x=2y+5
Please help me understand the method to solve. Penny Nom lui répond. 





Probabilities and olivies 
20040214 

Annetta pose la question : A bowl contains five green olives and eight black ones. Wilma sticks a fork into a bowl and brings out two olives. What is the probability that she gets one green and one black olive? Harley Weston lui répond. 





Red riding hood 
20040214 

Frank pose la question : Red riding hood had a number of jars to take to grandma's house. As she traveled she gave away 1/3 of them to an old lady. Then later As she walked through the forest a wolf stole 1/2 of her remaining jars. When she arrived at grandma's house she gave her 2/3 of the remaining jars. She kept 6 jars for herself. How many jars did she start out with. Diane Hanson lui répond. 





A pyramidshaped tank 
20040213 

Annette pose la question : The base of a pyramidshaped 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. 





Fractions 
20040213 

A parent pose la question : 12/36=?/18=4/?=?/9 Penny Nom lui répond. 





Common fractions to decimals 
20040212 

A parent pose la question : I'm trying to help my son work with turning fractions into decimals and this seems foreigh to me after 20 years of not being in school. Can you give me a few illustrations and/or examples of how to do that?? Penny Nom lui répond. 





Profit 
20040212 

Mohamed pose la question : if i bought some thing with 100$ and the saller told me that his profit was 30% how can i know the actual price of the good Penny Nom lui répond. 





Zero 
20040212 

Syazwan pose la question : can you tell me who and when the number zero was
discoveredd Penny Nom lui répond. 





Three numbers are added in pairs 
20040212 

Jane pose la question : When three numbers are added in pairs, the sums of the pairs are 22, 39, and 45. What are the three numbers? Penny Nom lui répond. 





Driving from Sarnia 
20040211 

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. 





Digits in the decimal expansion 
20040211 

Leslie pose la question : In the decimal expansion of 1/17 what digit is in the 1997th place? Penny Nom lui répond. 





Sums and differences 
20040210 

David pose la question : The sum of two whole numbers is 63. The difference between the numbers is 10. Find all the possible pairs. Claude Tardif and Penny Nom lui répond. 





Three times a year 
20040209 

Graham pose la question : What is the term for a report that is submitted three time a year or at the very least a prefix term for one third Harley Weston lui répond. 





Will be shinning in 36 hours? 
20040208 

Kim pose la question : It is noon, you lunch hour, but you cannot go out because there is a terrific hailstorm. Turning on you radio you hear that weathercaster predicts that the hail will change to rain and that it will pour all day today. How can you determine whether the sun will be shinning in 36 hours? Justify your answer. Penny Nom lui répond. 





Graphing lines 
20040208 

A student pose la question : how do you solve y=1\3x+3 and y=1\3x3 by graphing? Penny Nom lui répond. 





A/30 + B/105 = (7A + 2B)/x 
20040205 

Jim pose la question : If A/30 + B/105 = (7A + 2B)/x and A, B, and x are integers greater than 1, what must x equal? Penny Nom lui répond. 





A quadratic word problem 
20040204 

Carl pose la question : A walkway of uniform has 72m2 and surrounds a swimming pool that is 8m wide and 10m long. Find the width of the walkway. Penny Nom lui répond. 





$20,000 at 25% compounded daily 
20040203 

A student pose la question : Hi there, I'm tying to figure out how much interest I would pay on 20,000 if it was 25% compounded daily. Penny Nom lui répond. 





Geometric sequences 
20040203 

Alan pose la question : hello, I am a junior in precalculus. we started working on geometric sequences today, it makes perfect sense on how it works. but why is it called that? if you could send me an answer to why geometric sequences have that name, I would be much appreciative. Chris Fisher lui répond. 





The volume of a tetrahedron 
20040203 

Joseph pose la question :
How do I calculate the volume of a bird tetrahedron. I'm trying to find out to get extra credit. I came with this idea while making a origami tetrahedron.
Joseph
P.S. Do you by any chance have instructions for orig ami figures. If you do, please send me some. Thanks!
Penny Nom lui répond. 





The incline of an exercise machine 
20040202 

An exerciser pose la question : This is a question about incline percentage. On an exercise machine if the elevation is raised 3 and one half inches from a level position then what would be the incline percentage? Penny Nom lui répond. 





Angular speed 
20040201 

Rachel pose la question : A 4 inch pulley on a motor makes 1500 revolutions/minute. It is connected to an 8 inch saw blade.
a. Find the angular speed of the pulley in radians/minute
b. Find the angular speed of the saw in radians/ minute
Harley Weston lui répond. 





Logarithms 
20040201 

A student pose la question : Where did the word logarithmic come from? Where/whom did it originate? Harley Weston lui répond. 





Pairing boys and girls 
20040201 

Terri pose la question : Suppose 7 boys and 7 girls are assigned to work in pairs of one boy and one girl. Explain what equation can be used and how you would use a simpler problem to solve these types of questions. Penny Nom lui répond. 





The vertex of a cone 
20040129 

Richard pose la question : Please help me explain to my fourth graders as to why a cone has a vertex even though it does not have any straight edges. Chris Fisher lui répond. 





Intersecting a line and a curve 
20040129 

Senthil pose la question : between line and curve how can i
find intersection point?
could you write me the formula and explanation also sir. Penny Nom lui répond. 





Is a cylinder a type of prism? 
20040129 

Rebecca pose la question : Is a cylinder a type of prism? Penny Nom lui répond. 





Order of operations 
20040128 

John pose la question :
I am trying to find out any information concerning the development of the order of operations. for example, when (why/how) did it become the case that 2 + 3 x 5 =17, rather than 25.
any insight is appreciated. Thank you.
Penny Nom lui répond. 





Sin(3x), cos(3x) and tan(3x) 
20040128 

Jon pose la question : What is the identity for cos3x, sin3x, and tan3x? In class, we learned double angel identities and were asked to find out the identity to these three trig functions. If you can help, please do. Also, i know that the cos^{4}x sin^{4}x is the same as cos2x. Is cos^{8}xsin^{8}x = cos2x also true? Thank you.s Chris Fisher lui répond. 





Sets 
20040127 

Susan pose la question : My child has the following problems to solve, and we are puzzled.
1. Compare the subset symbols to the inequality symbols of less than or greater than.
2. If A, B & C are sets such that A has 47 elements, B has 32 elements, and C is a proper subset of B, what can you say about the number of elements in the following sets: A U B? A intersect B? B U C? and B intersect C? Penny Nom lui répond. 





The London marathon 
20040127 

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. 





Ounces into cubic centimeters 
20040127 

A student pose la question : how do you convert ounces into cubic centimeters? Ex: how does 12 oz. change into cc. Penny Nom lui répond. 





Three digit combinations 
20040127 

Kevin pose la question : how many 3 digit combinations can be made with 09. i have been told only 1,000. when i asked jeeves the response was 750 without using any digit twice. i have entered a raffle and received a ticket with 4 sets of 3 digit numbers. Penny Nom lui répond. 





Lead weights 
20040126 

Jeff pose la question : I am making a mold for my decoy anchors. I need
10  12 lead ounce weights. How would I determine the liquid measurement for that weight? For example if I melted down 10 ounces of lead how many cups would that be or quarter cups etc?
I would like the formula if I could and good instructions on how to use the formula. Penny Nom lui répond. 





Polynomials 
20040125 

Bruce pose la question :
A polynomial is defined as
Polynomial functions are functions that have this form:
f(x) = a_{n}x^{n} + a_{n1}x^{n1} + ... + a_{1}x + a_{0}
The value of n must be an nonnegative integer. That is, it must be
whole number; it is equal to zero or a positive integer.
The coefficients, as they are called, are a_{n}, a_{n1},
..., a_{1}, a_{0}. These
are real numbers.
Questions:
 why must n be positive?
 what are some historical facts
about the evolution of the definition?
Harley Weston lui répond. 





x^2  12x = 8 
20040124 

Sherre pose la question : x^{2}  12x = 8 Penny Nom lui répond. 





Bundles of asphalt shingles 
20040124 

Larry pose la question : According to my study material 4:12 multiplying factor for shingles is 1.054. The question reads as follows: A building with a floor plan of 3350 sq. ft. and a roof slope of 4:12 will require _______ bundles of standard asphalt shingles. Harley Weston lui répond. 





x^x^x^x^... 
20040123 

Ryan pose la question : you have a number say x and it is to the power of x which is to the power of x and so on infinite times like x^x^x^x^x^x^x^... i have to figure out what x is so that the answer is always 2 Penny Nom lui répond. 





A counterfeit coin 
20040123 

Kim pose la question : You are considering buying 45 silver coins that look alike, but you have been told that one of the coins is a lightweight counterfeit. Find the least number of weighings on a balance scale that you can use to be certain you have found the counterfeit coin? Penny Nom lui répond. 





g on Mars 
20040122 

RC pose la question : To measure the acceleration on Mars an object is dropped from a height of 160m. It takes 10s for this object to hit the ground. What is the value for g on Mars?g Penny Nom lui répond. 





A game with some strings 
20040122 

Trudy pose la question : A boy holds 6 pieces of strings in his hands with the ends protruding above and below. The top ends are tied together in pairs and then the lower ends are tied together in pairs. What is the probabilty that the pieces of string are all joined in one loop?
What is the probability of obtaining two loops?
Can you generalise this to solve the problem for 2n blades of grass? Andrei Volodin and Penny Nom lui répond. 





BEDMAS 
20040121 

Jessica and her mom pose la question :
my mom and I were wondering 2 things.
1. what is the reason for having bedmas.
2. 5+54+[6x3(6+13x2) 5+9]
Penny Nom lui répond. 





A problem with sets 
20040120 

Jason pose la question :
Given that the universal set S is the set of all sports fans, and
F={xx is a football fan}
B={xx is a basketball fan}
H={xx is a hockey fan}
a)Describe (F^B)' (f intersect b)' in words
b)Draw a Venn Diagram and shade the region that represents the set of football fans or both basketball and hockey fans.
Penny Nom lui répond. 





What is the speed of the automobile? 
20040120 

Rita pose la question : An automobile travels toward Nashville from Cookeville. It takes 33 minutes to travel from Cookeville to Manchester, which is a 36 mile distance. If the driver continues at this pace, what is the speed of the automobile? Penny Nom lui répond. 





A parabolic arch 
20040119 

Teresa and Robyn pose la question : A bridge over a river is supported by a parabolic arch...arch is 200 m wide at water level...the maximum height of the arch is 80 m..what is the height of the arch measured from a point on the water 40m from the centre of the arch Penny Nom lui répond. 





The product of any n consecutive integers 
20040118 

Fazia pose la question : I have to prove that the product of any n consecutive integers is divisible by n!(eg:the product of five consecutive integers is divisible by 5!) It's easy enough to plug in numbers and prove it is true, but i'm finding it difficult to come up with a proper proof. Claude Tardif lui répond. 





Combinations of 12 numbers 
20040118 

Cheryl pose la question : I would like to know the total possible combinations using the numbers 112. We would also like to know the formula used to calculate the number of combinations. Harley Weston lui répond. 





Cubic yards in a concrete wall 
20040118 

Danny pose la question : I am studing for my contractors exam. I am haveing truble with a few questions. I have the answer to the problems but I dont know how to get them my self. please help
How many cu. Yds. Of concrete are in a wall that is 150' long and 8'4" high an d 8' thick Penny Nom lui répond. 





Some trig problems 
20040118 

Weisu pose la question :
I have some questions about precalculus.
(1) (2(cos(x))^2)+3sin(x)1=0
(2) sin(x)cos(x)=(1/2)
(3) 3sin(x)=1+cos(2x)
(4) tan(x)*csc(x)=csc(x)+1
(5) sin(arccsc(8/5))
(6) tan(arcsin(24/25))
(7) arccos(cos(11pi/6))
the last problem uses radian measure.
Penny Nom lui répond. 





Two consecutive negative integers 
20040117 

Amanda pose la question : Find two consecutive negative intergers whose product is 182. Penny Nom lui répond. 





Six letter words 
20040117 

Debora pose la question : An anthropologist discovers an isolated tribe whose written alphabet contains only six letters (call the letters A, B, C, D, E, and F). The tribe has a taboo against using the same letter twice in the same word. It's never done. If each different sequence of letters constitutes a different work in the language, what is the maximum number of six letter words that the language can employ? Penny Nom lui répond. 





Arrays of pennies 
20040117 

Kathleen pose la question : How do I create an array of 100 pennies? Penny Nom lui répond. 





Volume of a tube 
20040114 

Mike pose la question : where can you find how to get volume of a tube:
3 in across x 3 inch high
5 in across x 5 inch high
same formula for both. ONE will get the other. Penny Nom lui répond. 





3/8 as a decimal 
20040113 

A student pose la question : My Math Midterm is tommorow and I am stumped... how do you turn 1 and 3/8 into a decimal... I know the answer is 1.375 but I just copied down what the teacher wrote on the board.
Oh, and what are the three cases of percents? Penny Nom lui répond. 





What is a Fact Family? 
20040113 

Keisha pose la question : I am helping my child with his homework. The worksheet we are trying to do ask the child to choose a number from inside of a circle and then one from inside of a triangle and use the number to build a fact family. The title of the worksheet is "Building a Fact Family House". I noticed that Silver Burdett Ginn,Inc. was the publisher of the book the worksheet came from so I was on the website trying to find an answer to my question. My question is "What is a Fact Family?" Judi McDonald lui répond. 





Polynomial division 
20040113 

Efrat pose la question :
How do we divide the following polynomials?
(x^{3} + x^{2}  x + 2) / (x + 2)
Penny Nom lui répond. 





Twelve acres 
20040113 

Heather pose la question : I am looking at buying a property that includes 12 Acres of land and I am trying to visualize what this size is equivalent to. I have searched your site and figured out how many square feet it is but I was hoping that you could apply 12 Acres to something tangible, like a football field! Penny Nom lui répond. 





Why is the letter J used for the integers? 
20040113 

Amanda pose la question : Why is the letter J used to represent intergers as a symbol? Penny Nom lui répond. 





The square footage of an acre 
20040112 

Paul pose la question : What is the square footage of an acre of land assuming all four sides are
equal in length. Penny Nom lui répond. 





Permutations and combinations 
20040111 

A student pose la question : Are there more permutations than combinations for a series of 4digit numbers with the integers 09? Can you illustrate calculations? Penny Nom lui répond. 





Cubic furlongs 
20040111 

A student pose la question : 1 mile=8 furlongs, how many cubic furlongs in a cubic mile? Penny Nom lui répond. 





Reflex angles 
20040109 

Sonya pose la question : My daughter is searching for examples of reflex angles. We already have the hands of a clock but still need another example. Can you help us. Chris Fisher lui répond. 





Geoboards 
20040109 

Elissa pose la question : What is a geoboard? I have a young girl in grade eight math who has a math
question using a geoboard. Diane Hanson lui répond. 





The area of a lot 
20040109 

Lea pose la question :
I have a problem. I am interested in purchasing a piece of property which has the following dimensions. It is 259.10 Feet on the north side x 61.20 Feet on the east side x 217.80 Feet on the south side x 196.70 Feet on the west side. It looks like an irregular rectangle shape. How do you figure out the square footage on this irregular sized property, and what is the correct square footage answer.
I have attached a survey map. Harley Weston lui répond. 





Inequalities 
20040108 

Michael pose la question : How do you use inequalities in your job and in your everyday life? Penny Nom lui répond. 





Dividing zero by infinity 
20040108 

Jason pose la question : What do you get when dividing zero by infinity? Our Calculus teacher was pretty sure that the expression was indeterminate from. However, if this is so...Why? Zero divded by any number (except zero) is zero, true. Any number (except infinite) over infinite is zero. So, why isn't Zero divided by infinite zero. A simpler way if I had 4 potatoes and was to split them among 2 friends, each friend would get 2 potatoes. However, if I had 0 potatoes and split them a infinite number of ways, each person would still have 0. Explain please! Penny Nom lui répond. 





Unusual occurances 
20040108 

Martin pose la question : My wife and I have a question about the probability of something that happened to us a few years ago. So far, no one has been able to give me even an approximate answer. On my 32nd birthday, my wife and I went out to eat at local Japanese hibachi style restaurant. At the restaurant, couples/families are sat together around the hibachi where the cook performs a show. There was a fifteen minute or so wait, so my wife and I sat in the lounge waiting for our name to be called. When they called our names for the reservation, this is what happened. The first group called was the Martin family. Then they called the Francis family. We were the next family to be called, the Ashton family. My full name is Martin Francis Ashton! I think the odds of that happening to someone are very unlikely, but it did, and there is more. Next, we were all sat at the same table in that order, "Martin" family, "Francis" family, then us, the "Ashton" family. Again, it formed my full name! Penny Nom lui répond. 





Is zero even? 
20040107 

A secretary at an elementary school pose la question : Is zero an even number? Penny Nom lui répond. 





The sides of a circle 
20040107 

Helena pose la question : My name is Helena and I am 10 years old. On a resent math exam I was asked
the question" How many sides does a circle have?" and I wrote down none. The
teacher said the answer was one side. Chris Fisher lui répond. 





Laying decorative bricks 
20040107 

Duk pose la question : Loren is laying decorative brick along both edges of the 21meter walkway up to his house. Each brick is 0.26 meters long. He is placing the bricks end to end. How many bricks does he need to do the job? Penny Nom lui répond. 





Factoring expressions 
20040103 

A student pose la question :
I'm having trouble factoring expressions that aren't monic. I can do things like
x29x+8, but problems like 12x2+5x3 have me stumped.
I also have a question about factoring out common factors. In a problem like
x218x+81, wouldn't you divide by 9? But what happens to the x2, is it x2/9? Penny Nom lui répond. 





37 with four 4'2 
20040103 

Myra pose la question : Using four fours and only four fours to get an answer of 37. Claude Tardif lui répond. 





Solving an equation 
20040103 

A student pose la question : the question is to solve and check equations and the question is
2n + 3n + 7 = 41 Penny Nom lui répond. 





Making a windmill 
20040102 

Matthew pose la question : I am a farmer in Ontario. It has been almost 20 years since high school. I am toying with making a windmill. The output chart for the the old generator I have is shown below. Before I tear it appart I would like to develop a formula from the chart that can predict the output at various speeds. Penny Nom lui répond. 





Four digit combinations 
20031231 

A student pose la question : i need all 4 digit combinations using 09 please Penny Nom lui répond. 





Fractions 
20031231 

Jae pose la question : Replace the question marks with numbers that will make the sentence true.
1.1/3=?/9=?/6
2.?/18=8/12=4/?
3. 3/?=12/?=9/?
4.?/3=?/21=?/7
5. Which problems have more than one possible answer? Why do you think this is so? Penny Nom lui répond. 





A new way to measure randomness 
20031231 

Stephanie pose la question :
Last year, I did a science project in which I asked, "Which shuffles better, an automatic card shuffler or shuffling by hand?" To measure this I decided the "best" shuffler was the one to become random first. Last year, to measure randomness, I numbered cards 152 and had the subjects shuffle them until they broke up the rising sequences or reached 10 shuffles. (Usually 10 shuffles came first...) Anyway, I did the same thing with the automatic card shuffler, and, as hypothesized, the automatic card shuffler randomized the deck first.
This year, I have decided to continue the project. The problem is, I need a new way to measure randomness without the use of fancy computers or something. I have searched the Internet, I have posted my query on websites based on math, and I have searched the local library.
I have found many useful things on the Internet, but none of them can tell me a new way to measure randomness. I cannot do a perfect shuffle, and I am not terribly gifted in the art of using computers. If you have any information (anything will help) or advice, I would be greatly obliged. Andrei Volodin lui répond. 





The trapezoidal rule 
20031231 

Prashanth pose la question : I have a set of XY coordinates(say 49 points),I want to find the area enclosed by the curve joining them and the axes.I do not have an equation for the curve and I am not able to fit a curve given the points.I use the trapezoidal rule
(Y1+Y2/2)*(X2X1),
Is it right? can I do this with any other method? Penny Nom lui répond. 





Ratios and proportions 
20031231 

Frank pose la question : I would like to know how you use 'ratios and proportions' in everyday life. Penny Nom lui répond. 





Some number problems 
20031224 

Shruthi pose la question : 1. Write 31 using 3 five times
2. Write 100 using all the 10 digits just once
. . . Penny Nom lui répond. 





Percent increase 
20031224 

Frank pose la question : How does one figure the percent of increase or decrease in the cost of an item? Penny Nom lui répond. 





Making a cone 
20031222 

Tracie pose la question :
I am working on a craft project at home and I have been given the following information: 16" tall and 13" diameter at base, with 1 and 1/2 " opening at top.
Is there a basic formula for creating a cone with this info?
Claude Tardif and Penny Nom lui répond. 





400, 100 and 2500 
20031221 

A student pose la question : A person likes 400 but dislikes 300
He also likes l00 but dislikes 99
He also likes 2500 but
dislikes 2400
Which of the following does John like
900, 1000, 1100 or 2400
Penny Nom lui répond. 





The angles in a regular polygon 
20031221 

Ernie pose la question : If i have a measure of one interior angle of a polygon, how can i find the number of sides it has? Penny Nom lui répond. 





Adding percentages 
20031219 

Paula pose la question :
How do you add percentages
e.g 90% + 80% + 60% + 54% + 25% = ?
Penny Nom lui répond. 





Business trip 
20031219 

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 1hour 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 45minute 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. 





The area of a plot of land 
20031219 

David pose la question : I have a plot of land that I cannot find the square footage of. Actually my home sits on a large lot. Local building codes require that a home is seated on no less than 7500 square feet of land and have no less than 50ft of road frontage (the rear of the lot has 65ft of frontage on another road). I need to know if I have enough square footage to build a second home on the rear lot. The lot has five sides. Only one angle is a 90 deg. angle. The others I cannot determine. Of the 4 remaining angles, all 4 angles are obtuse, or greater than 90 deg. The dementions are 89.19' x 130' x 118.52' x 65' x 170.94'. The two legs that make the 90 deg angle are 89.19' and 170.94'. The measurements fall in order using the 90 deg angle as the point of origin and proceeding clockwise, 89.19', 130', 118.52', 65', 170.94'. I have used all the skill I can muster, however, it has been a long time since school and regretably I cannot find an answer. Penny Nom lui répond. 





Multiplier and multiplicand 
20031217 

Karen pose la question : The K5 curriculum states that at a grade 5 level students should "understand and use the terms multiplier, multiplicand" The curriculum defines 'multiplicand' as " a number being multiplied by another number. A factor." There is no definition given for 'multiplier'
Question: Define these words are they just other words for 'factors'. If so, how important is it that students use these terms? It would seem like 'factors' would be the better choice of words to use. If multiplcand refers to eg. the first factor in the equation and the 'multiplier' the seond term, (if in fact it does) is this not confusing for students when we teach them that multiplication is commutative? Penny Nom lui répond. 





Binomial distribution 
20031217 

Lesley pose la question : my daughter is having difficulty with the following formula
P(X=x) = ( n over x) px (1p) nx
The teacher has given them the formula but not taught them how to apply it or understand it. Penny Nom lui répond. 





The hour hand and the minute hand 
20031217 

Minnie pose la question : When you are looking at the clock at 12:00 the hour hand and minute hand are exactly together. (one on top of the other). Between 1:00pm and 1:15pm there is another time when the hour and minute hands are exactly together again. Penny Nom lui répond. 





Factoring in 
20031216 

Priscilla pose la question : How can you use solving by factoring in real life applications? Harley Weston lui répond. 





An elliptical race track 
20031216 

Judy pose la question : the inner rail of a race track is a perfect ellipse. the track is a standard width all the way around. how can i prove that the outer rail is a ellipse? Penny Nom lui répond. 





How far can you see? 
20031215 

Judy pose la question :
How far apart, assuming no obstacles, can two people stand and still see each other?
i know this deals with the curvature of earth, but i can't figure out the formulas involved.
Chris Fisher lui répond. 





(2^ 20,966,011)  1 
20031212 

Reid pose la question : Can someone please explain, answer and/or solve this: (2^ 20,966,011)  1
I don't know what it means, my boss sent it out, I'm assuming it is to be
solved but don't know what it is, any prompt help would be appreciated, very
much so, in fact, thanks,........... Penny Nom lui répond. 





Math jobs 
20031212 

Veronica pose la question : Do you know a couple of jobs I can get when I am older in Math? Harley Weston lui répond. 





A snowball melts 
20031211 

Adam pose la question : A spherical snowball has diameter 10cm and density 0.75g/cm3. It is placed in a cylindrical can with diameer 12cm. After the snow melts it turns to water with density 1.0g/cm3. What will be the depth of the water in the can (to 1 decimal place)? Penny Nom lui répond. 





Diamonds and Pearls 
20031211 

Lauren pose la question : A crown holds a total of 3080 jewels.
It is made up of diamonds and pearls.
There are 10 times as many diamonds as there are pearls.
How many pearls are there? Penny Nom lui répond. 





1/0 = ?? 
20031209 

Lisa pose la question : One of my students asked me a fractions question. She knows that 0/1
equals 0 but does 1/0 also equal 0? Walter Whiteley and Penny Nom lui répond. 





Noneuclidean geometry 
20031208 

Geoffrey pose la question : How can you use noneuclidean geometry to navigate on a sphere? What geometers did work in this area? Chris Fisher lui répond. 





Matrices 
20031205 

Julie pose la question : I am doing a project and need to find some mathematiciens who had an influence in matrices. I can't seem to find any when I search online. Could you please help me with this? Judi McDonald lui répond. 





Prescription drug coverage 
20031204 

Khadijah pose la question : Last week congressional approval was given to legislation involving prescription drug coverage for seniors. One summary of the legislation explains that it is estimated that in 2006 a senior will pay a premium of $35 per month, then pay their first $250 in pharmacy bills. After the bills reach $250, the coverage would pick up 75% of their bills that bring their total bills between the $250 and $2250 mark. After their bills reached a total of $2250, the senior would be responsible for all bills bringing their total annual bills between $2250 to $5100. Then any bills after the $5100 mark has been reached will be 95% covered by the insurance. Using this information, letís analyze the situation of a senior who accumulates $6000 in pharmacy bills over one year and has the insurance coverage. Over the course of this year, how many dollars will the senior pay? Penny Nom lui répond. 





What percentage of 6 billion is 40 million? 
20031203 

GiGi pose la question : What percentage of 6 billion is 40 million? Penny Nom lui répond. 





The median 
20031203 

Christiane pose la question : how do you find the median of this group of numbers:63,75,29,37,49? Penny Nom lui répond. 





NonEuclidean geometry 
20031203 

Geoffrey pose la question : What are the applications of NonEuclidean geometry (especially hyperbolic and spherical)? Walter Whiteley lui répond. 





Four digit combinations 
20031202 

Deen pose la question :
Question:
i have 3 numbers and i have to come up with all the possible 4digit combinations with those 3 numbers. Is there a formula for it?
Example:
given numbers are 129 and you need to break a 4 digit code. what are the posiible combinations that u can come up using the 3 numbers?
Penny Nom lui répond. 





A locus 
20031202 

Tash pose la question :
Question:
a)Find the equation of the locus of the point P which moves so that its distance from A(1,2) is always three times its distance from B(5,6)
b) Show that this locus is a circle and states the coordinates of its centre and the length of its radius
Penny Nom lui répond. 





Finding angles 
20031202 

Jason pose la question : I AM TRYING TO SOLVE A TRIG PROBLEM AND HAVE
FORGOT HOW TO DO IT. WHAT I HAVE IS A RIGHT TRIANGLE WITH SIDE A BEING 14
FEET AND SIDE B BEING 3 FEET, USING PYTHAGOREAMS THEOREM SIDE C SHOULD
EQUAL 14.318 FEET ON A RIGHT TRIANGLE BUT I AM TRYING TO REMEMBER HOW TO
FIND MY ANGLES OTHER THAN THE ONE THAT IS 90 DEGREES. Penny Nom lui répond. 





The area of a triangle 
20031201 

A student pose la question : Find the Area of Triangle ABC
A(3,2)
B(4,0)
C(0,8) Penny Nom lui répond. 





Room and board fees 
20031129 

Jennifer pose la question : A certain university wishes to determine room and board fees for the next academic year. For the current year, the fee is $3600 per student and 1800 students are living in the residence halls. Past data suggests that for every $300 increase in the semester fee, 200 fewer students will choose to live in the dorms. There are also costs to the university associated with the residence halls. The fixed costs total $2,000,000 per semester. the variable costs are currently $1000 per student but will fall $100 per student for each decrease of 100 students. Your task is to help the university determine the optimal fee. Assume linear relationships between the number of students and the fee and between the number of students and the cost per student Penny Nom lui répond. 





5.75 acres of land 
20031128 

Susan pose la question :
We own 5.75 acres of land here in El Paso Tx.
Some one wants to buy all or some of our land...to build homes on...but.. I can't figure a few things
1. our land is Almost exactly 500x 500x500 x500 ft square proprty
based on this can you tell me the approx perimiter measurements of EACH acre
we wish to sell approx 1/2 of this 5.75 acres ...or a tad bit less.. these are all approx measurements
what I also need to know is.. how many 50ft x 100ft lots are in each (1 )Acre???
Penny Nom lui répond. 





A fish tank 
20031126 

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. 





Mr.Carter is very cautious 
20031126 

Bob pose la question : Mr.Carter is very cautious. He decides to invest in only three stocks: one low stock, one high stock, one medium stock. Given that the expected annual yields are 6% for low stock, 7% for medium stock, and 8% for high stock, he wants his investment in medium stock to be half of his total investment in low and high stock. How much should I invest in each type fo stocks to expect a total annual return fo $650 form my investments? Harley Weston lui répond. 





Area of an equilateral triangle 
20031125 

Jared pose la question : Can you help me understand why the area of a equilateral triangle is the square root of 3 divided by 4 times the lenght of the side squared? Penny Nom lui répond. 





An inequality whose solution is all points 
20031125 

Katie pose la question :
Hi my name is Katie and I am in the 9th grade and I would like help on this question. Is it possible to have a system of inequalities whose solution is all points?
1.I need to know why (explanation)
2.how to do it(example)
Penny Nom lui répond. 





The volume of an irregular tetrahedron 
20031124 

Peter pose la question : How do I calculate the volume of an irregular shaped tetrahedron where: side a = 1.4 m side b = 1.4 m side c = 1.2 m and height = 0.75 m at the junction of sides a and b. Penny Nom lui répond. 





Markup, profit and margin 
20031124 

Ali pose la question : I have question regarding Margins, Markups and Profit
Purchase price = $ 10.00
Margin or Markup ?? = 40 %
Therefore Selling Price = 10/0.6 = $ 16.67
Profit ? = (16.6710)/10 *100 = 66.67%
or is the profit = (16.6710)/16.67*100 = 40 %
Can you please clarify What is Margin, Markup and Profit Penny Nom lui répond. 





Difference of squares 
20031124 

Susie pose la question :
Factor assuming that n is a positive #
Problem: (I will give it to you in words beacuse I don't know how to do exponents on the computer.)
Fortyfive r to the 2n power minus five s to the 4n power.
I was hoping you could walk me through it not just give me the answer.
Penny Nom lui répond. 





An octagon shaped bed frame 
20031123 

Trish pose la question : My son and I are making an octagon shaped bed frame. We are going nuts trying to figure out what angle to cut the boards to make an outline of an octagon. It seems that the 8 inside angles of the 8 "corners" are 120*, but what is the angle that the 2x6 wood should be cut so that they will angle together to form the outline of the octagon? Penny Nom lui répond. 





Laws of sines and cosines 
20031123 

A parent pose la question : On the one side of a stream lines PA= 586.3 feet, PB = 751.6 feet are measures, angle APB being 167 degrees and 36 min. Q is a point on the opposite side of the stream. Angle PAQ=63 degress and 18 min and PBQ=49 degrees and 24 min. Find PQ. Penny Nom lui répond. 





The volume of a cube 
20031122 

A student pose la question : i have a cube, and the line that cuts threough the middle of the cube across to the other side is 4 radical6. what is the volume of the cube? Penny Nom lui répond. 





Aristotle 
20031121 

John pose la question :
I would like to know how aristotle was related to math.
In all my searches I have found only philosophy etc.
But not any math.
Penny Nom lui répond. 





AB/AP=AP/PB 
20031120 

James pose la question : My name is James McBride. I'm having a difficult time with a pre calculus problem, which goes as follows: "show that AB/AP=AP/PB is equal to (1+5^1/2)/2 (one plus the sqaure root of five with the sum divided by two. I can't do the square root sign, sorry.) I have tried to solve for PB in terms of the other varialbles and then work the quadratic equation. THAT DOES NOT WORK!!!! I am befuddled. Please help me. I am a student of secondary level. Penny Nom lui répond. 





Four digit numbers 
20031120 

Rob pose la question : Hello, I sure hope you can answer this question. I got into a discussion at work about how many possible combinations there are for a four digit number using the numbers 0 through 9. This was in reference to a discussion about the lottery. I said there was only 10,000 possible combinations. My friend said that there was many times more, but he could not remember how to figure it out. The answer and the formula would be greatly appreciated. Penny Nom lui répond. 





962 Sq. Ft. is what percent of 2656 Sq. Ft 
20031120 

Jon pose la question : 962 Sq. Ft. is what percent of 2656 Sq. Ft Penny Nom lui répond. 





4(r2) = r(2+8) 
20031120 

Angela pose la question : I not going to give you the problem that I have, but a problem like it.
4(r2) = r(2+8)
I get mix up trying to solve a problem like this could you help me. So that I will be able to handle the ones on my homework. Penny Nom lui répond. 





A riddle 
20031119 

Sarah pose la question : Ok, our teacher gave us this riddle, and I cannot for the life of me figure it out. He said that there are three problems with the following proof: Penny Nom lui répond. 





Systems of equations 
20031119 

Scott pose la question : I hope that u can help me....I
am a college student taking a class in Pre Calculus.....I have homework
due this Friday and it counts a BIG Percentage on my FINAL grade.....I
am getting mixed up and can not figure out a few problems.....Please help
me.....
Method Of Subsitution
Problem 1. y 8x = 5
x(squared) + y(squared) = 25
Problem 2. y = x(squared)  2x  6
Y = x(squared)  4
Penny Nom lui répond. 





A point and a line 
20031119 

Meenakshi pose la question :
Given a line segment L(x_{1},y_{1})
to (x_{2},y_{2}) and a Point P(x_{3},y_{3}).
I need the formula to find a point on the line L that is closest to
the point (x_{3},y_{3}). Penny Nom lui répond. 





If 1 is neither prime nor composite... 
20031119 

Joshua pose la question : if 1
is neither prime nor composite...what is it called? Claude Tardif and Penny Nom lui répond. 





If 1 is neither prime nor composite... 
20031119 

Joshua pose la question : if 1
is neither prime nor composite...what is it called? Claude Tardif and Penny Nom lui répond. 





Unmatched socks 
20031117 

Shannon pose la question :
i have 6 pairs of socks lying unmatched in my dresser drawer. Each pair is a differnt color (brown, black, red, yellow, green, purple) When i wake up in the morning, I randomly grab 2 of the loose socks and put them on without looking.
If two socks are randomly selected from the drawer, what is the probability that they match?
Andrei Volodin lui répond. 





The 4th difference 
20031117 

Jack pose la question : If i had a sequence which was the same at the 4th difference, aka difference
to the 4th, like:
1 5 14 30 56 96
(sequence)
4 9 16 26 40
5 7 10 14
2 3 4
1 1
then what would be the set formulars to find out a, b, c, d, and e
as i know the equation has to be an^{4}+bn^{3}+cn^{2}+dn+e Penny Nom lui répond. 





Adding fractions 
20031116 

Ken pose la question : My name is Ken and I am taking my GED course for my High School and have not been in a class for 35 years. I am doing this for retraining. I am at the part about fractions. Here is an example that I am having trouble with.
1 3/7 + 4 2/3 + 11/21
They have no common denominators. Could you PLEASE help me. If you could send me a step by step explanation it would be greatly appreciated. Penny Nom lui répond. 





Three problems 
20031116 

Megan pose la question : My name is Megan and I am a junior in high school. Our teacher gave us a few xtra credit questions and I need some help. Penny Nom lui répond. 





Divisibility by 7 
20031114 

A student pose la question : how do you test a number to see if it is divisible by 7 or not? Penny Nom lui répond. 





Lines 
20031114 

A student pose la question : What is a name that a group of lines pass through? Chris Fisher lui répond. 





root24 = 2 root6 
20031113 

Burke pose la question : I know that all algerbra can be represented visually, for example: Y=9x+3 is a line on a two dimentional plane. Could Math Central please send me a visual representation of the proccess of simplifying square root like root24 equals 2root6 Penny Nom lui répond. 





Diagonals in an octagon 
20031113 

Glenn pose la question : Question 1. What is the probability of choosing the longest diagonal in an octagon? Question 2. Probability of choosing the shortest? Andrei Volodin and Penny Nom lui répond. 





A trig identity 
20031112 

A student pose la question : I can't prove this identity. Can you please help me? (1tanx)/(1+tanx)=(1sin2x)/(cos2x) Penny Nom lui répond. 





What is a number that has exactly 13 factors? 
20031109 

Mary pose la question : What is a number that has exactly 13 factors? Penny Nom lui répond. 





Mixing Brazil nuts and cashews 
20031109 

Bob pose la question : Cashews are sold for 1.20 per 1/4 pound and Brazil nuts are sold for $1.50 per 1/4 pound. If you mix 20lbs of Brazil nuts, how many cahsews would it take to make a mix that sells for $1.30 per 1/4 pound? Penny Nom lui répond. 





A least squares line 
20031109 

Michelle pose la question : Hooke's Law asserts that the magnitude of the force required to hold a spring is a linear function of the extension e of the spring. That is, f = e0 + ke where k and e0 are constants depending only on the spring. The following data was collected for a spring; e: 9 , 11 , 12 , 16 , 19 f : 33 , 38 , 43 , 54 , 61 FIND the least square line f= B0 + B1x approximating this data and use it to approximate k. Penny Nom lui répond. 





Greatest Common Factor 
20031108 

Beth pose la question : How do you use the Greatest Common Factor in addtion and subtraction of fraction? Penny Nom lui répond. 





Equal ratios 
20031107 

A student pose la question : In the ratio 3:8=17__, can__be a whole number? Penny Nom lui répond. 





The product of the page numbers 
20031107 

Morgan and Mom pose la question : You open a book and the product of the page numbers is 12,656. What are your page numbers? Penny Nom lui répond. 





Chisenbop 
20031106 

Jaclyn pose la question : Hi there i was wondering if you would have any information on "counting on your fingers" or " Chisabop". Penny Nom lui répond. 





Intercepts 
20031104 

A student pose la question : I am totally confused on how to determine intercepts of an equation and then to graph the line. For example, how to determine the intercepts of 2x3y12=0. Penny Nom lui répond. 





X bar 
20031104 

mary pose la question : Remind me what this means:
_
X
Andrei Volodin lui répond. 





The length of a chord 
20031103 

David pose la question : When Radius=400.00' and Arc=130.58' what is the Cord distance in feet? Penny Nom lui répond. 





A circle around an irregular polygon 
20031103 

Dale pose la question : How do I find the properties of a circle that is drawn around an irregular polygon of (n) sides with the lenghts of each side given and all end points of the polygon lye on the circumferance of the circle? Chris Fisher lui répond. 





Solve for Q 
20031103 

Anwaar pose la question :
The problem is: QT  X ________ + H = HT QS Peny Nom lui répond. 





Cubic yards of concrete 
20031102 

John pose la question : The foundation is 20' X 20' and the depth is 6", there are also three footings that are 20' X 12" X 12" each. Can you show me the equation to figure out how many yards of concrete I will need to pour the footings and foundation. Harley Weston lui répond. 





Symmetries of a rhombus 
20031102 

Tonia pose la question : why cant an equal sided rhombus have 3 lines of symmetry? you have one line of symmetry on each of the diagonals, and there should be one vertically on an angle. can you please explain the rules of symmetry to me? Walter Whiteley lui répond. 





Which one has the most factors? 
20031031 

Kristi pose la question : Of all the whole numbers less than or equal to 5000, which one has the most factors? Claude Tardif lui répond. 





Divisibility by 2 or 5 or both 
20031030 

Abdu pose la question : How many positive integers less than 1,001 are divisible by either 2 or 5 or both? Penny Nom lui répond. 





1/x + 1/y = 5/12 
20031030 

Ben pose la question : 1/x +1/y =5/12, what is the sum of x and y? Penny Nom lui répond. 





12 cookies 
20031029 

Joel pose la question : there are 12 chocolate, sugar and cinnamon cookies. the probability of choosing a chocolate cookie is 1/3. the probability of choosing a sugar cookie is 1/4 what is the probability of choosing a cinnamon cookie Penny Nom lui répond. 





A rectangle on a disk 
20031029 

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. 





How much time? 
20031029 

Lori pose la question : I am a elementary teacher 36 math. We have just implemented the Houghton Mifflin Math curriculum. It seems to be quite difficult for most of our students. In order to get through all the material we need to do a lesson a day. Although the students are not getting the material that fast. Should we move on without all the students understanding the material or should we wait and remediate until they get it and be behind for the year. This isn't just a few kids its most of the kids. We are also suppose to teach to all the standards so if we don't get to them the students will not do well on the standardized tests. Diane Hanson lui répond. 





Trees 
20031028 

Ali pose la question : Is there any formula for counting the number of trees (graphs)? Denis Hanson lui répond. 





Means 
20031028 

Abdu pose la question :
Question: 80,80,84,85,88,92,97,98 The average of the 8 numbers listed above is 88. Of the following which pair of numbers could be removed from the list without changing the average. A. 80 and 97 B. 80 and 98 C. 84 and 92 D. 84 and 97 E. 85 and 92 Andrei Volodin and Penny Nom lui répond. 





Solve for x 
20031027 

Lonnie pose la question : i need help with solving equations and formulas such as 3x+b=6x, for x. I do not understand how you find x. Penny Nom lui répond. 





Knitting gauge and felting 
20031027 

Sara pose la question :
I wish to create a pattern to knit an item that will then be felted, thus, shrink as a result. In order to determine the proper gauge to use in creating the item, I produced a gauge swatch, noted the original properties and then the postfelting properties. They are as follow: Before Felting: 20 stitches(width) x 20 rows(height)yielded: Gauge: 3.2 stitches(width) and 4 rows(height) = 1" Dimensions: 6.25"(width) x 5.25"(height) After Felting: 20 stitches(width) x 20 rows(height) Dimensions: 4"(width) x 3"(height) How do I calculate the percentage change in size to accurately determine the number of stitches and rows needed to produce the desired dimensions for the finished (felted) item? Penny Nom lui répond. 





A rock on a string 
20031026 

A student pose la question : a rock on a 4' string is rotated at 80 rpm. what is the linear speed in feet per second? in miles per hour? Penny Nom lui répond. 





Maine and Nevada 
20031024 

Jimmy pose la question :
From 1989 to 1990, the population of Nevada increased b y 157,000, and that of Maine increased by 30,000. In 1990, the population of Nevada was 1,206,152, and that of Maine was 1,233,223. If the populations of the two states continue to increase at the same rates, when will the populations of Nevada and Maine be the same? Write a verbal model for this problem Write an equation for the model Solve the equation and answer the question. Penny Nom lui répond. 





A parabola 
20031024 

Delores pose la question : Given the vertex (4, 2) y intercept = 6 find if/where the parabola crosses the x axis? Penny Nom lui répond. 





0.810 and 0.801 
20031024 

Ahmed pose la question :
could you please tell me what is the greatest decimal fraction formed of the digits 0, 1 , 8? Is it 0.810 or 0.801, please give me the reason of the answer in details and the references if it possible. Penny Nom lui répond. 





Odd Pythagorean triples 
20031023 

Kathleen pose la question : in a triple can a and b be odd numbers Penny Nom lui répond. 





Arithmetic in bases other than 10 
20031022 

Kim pose la question : how do you add, subtract, multiply and devide in base 3, base 5, etc? Penny Nom lui répond. 





Squares in a rectangle 
20031021 

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. 





0.3 trillion 
20031020 

Bill pose la question : What is .3 of one trillion? Penny Nom lui répond. 





Domain of a function 
20031014 

Karim pose la question : Find the Domain of the Function H(x) = Log3 (4x + 7)10 H(x) = log base 3 times 4X plus 7 minus 10 i am having problem solving these kinds of problems. Penny Nom lui répond. 





Pairs of prime numbers 
20031013 

Nikolas pose la question : Use pairs of prime numbers to find all the numbers less than 50 that have only two prime factors. Make an organized list. Penny Nom lui répond. 





5x  y 
20031011 

Candace pose la question : math problem 5xy for x=12 and y=14 do you mulitilpy 5x12 and than the answer from 14 which gives you 46? is this right Penny Nom lui répond. 





Points inside a triangle 
20031010 

Laura pose la question :
is there a way to establish, if a given point at coordinates (x,y) is within an area defined by three other sets of coordinates forming a triangle ABC? is T(x,y) within triangle A(x,y)B(x,y)C(x,y) Chris Fisher lui répond. 





Statistics from grouped data 
20031009 

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. 





10,000 
20031008 

Nathan pose la question : what two numbers make the product of 10,000. Neither number can end in a zero Penny Nom lui répond. 





Interest compounded daily 
20031008 

Terie pose la question : If I owe $2000.00 @ 6.25% compounded daily for 54 days. How much do I owe in interest? Penny Nom lui répond. 





Standard Deviation 
20031007 

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. 





Two chords 
20031007 

Lori pose la question : Chords AB and CD of circle O intersect at E. If AE=4, AB=5, CE=2, Find ED. Penny Nom lui répond. 





The sketch of a graph 
20031007 

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)x^{3}2x^{2}+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. 





Arrangements around a circular table 
20031007 

Lori pose la question : How many arrangements can 6 people be seated round a circular table? Penny Nom lui répond. 





Indeterminate forms 
20031006 

A teacher pose la question : Is it possible for me to find any geometrical interpretation without using calculus to explain indeterminate forms? Chris Fisher lui répond. 





Functions, graphs and derivatives 
20031005 

Jathiyah pose la question : I wanted to know how would you tell (on a graph diplaying two funtions), which funtion is the derivative of the other? Walter Whiteley lui répond. 





The slope of a tangent 
20031001 

A student pose la question :
find the slope of the tangent to each curve at the given point f(x)=square root 16x, where y=5 Penny Nom lui répond. 





A rectangle in a circle 
20030927 

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. 





Relatively prime 
20030927 

James pose la question : what is the definition a relative prime numbers? Penny Nom lui répond. 





0/0 
20030925 

Thomas pose la question : How is 0/0 ever defined. Penny Nom lui répond. 





Absolute value 
20030923 

Crystal pose la question : I am trying very hard to understand Absolute Value, and I cannot seem to grasp the idea. I do not know why we use it, what the point of it is. I do not know how to use it. I know that it is always positive or zero, and I assume it relates to distance, but how can you use it in equations. Please explain it to me as simply as possible, thank you. Walter Whiteley lui répond. 





The golden ratio 
20030923 

Phillip pose la question : The Golden Section can be made from an equilatereral triangle inscribed within a circle. The Golden Section is achieved by joining the mid points of two arms of the triangle to the circumference. I can prove this by erecting a perpendicular to the line outside the circle, but am interested to see how it can be proved from within the circle. Chris Fisher lui répond. 





Primes 
20030923 

Julie pose la question :
#1. Suppose you are given a number (n) and told that 1 and the number (n) divide into (n). Does that mean (n) is prime? #2. Suppose that p is a prime number greater than or equal to 3. Show that p+1 cannot be a prime number. Penny Nom lui répond. 





The Sieve of Eratosthenes 
20030918 

Lynn pose la question : My daughter has been asked to find all the prime numbers by using the Sieve of Eratosthenes. I have no understanding what this means. Penny Nom and Claude Tardif lui répond. 





1 + 1 = 10 
20030917 

David pose la question : could you please explain to me how 1+1=10 thanks Penny Nom lui répond. 





Applications of logarithms 
20030916 

A student pose la question : I have a project due in my algebra two class dealing with logs and where they are used in life, but I am having trouble finding websites that relate. So I would really appreciate it if you couldhelp me. Penny Nom lui répond. 





Notation 
20030915 

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. 





Substitution method 
20030914 

John pose la question :
Hello, my name is john and while I was finishing up my work I stumbled into these problems. a/4b=1 a+b=11 and 6ab=5 4a3b=8 Thanks a lot. I really need some help :) John Penny Nom lui répond. 





The volume of an earthen pit 
20030912 

Bruce pose la question : This shape would occur at the four corners of a rectangular shaped earthen pit with sloping sides (1:1.5). Depth is 14'. Top dimensions are 170' by 158'. After calculating the easy volume components of this shape, we are left with the end corner pieces. 21' base, 14' height, side hypotenuse 25.24' and corner diagonal 32.83'. We're confused. Thank you for any help you may provide. Penny Nom lui répond. 





The digits in 349 
20030912 

Franik pose la question : in the number 349, which number has the least value, and why? Penny Nom lui répond. 





Two line segments and a plane 
20030911 

Laura pose la question : Do all figures made up of two segments lie in a plane? Penny Nom lui répond. 





Area of a rectangular room 
20030911 

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. 





The general equation for a sphere 
20030911 

Jaidev pose la question : Is there any general equation for a sphere? Penny Nom lui répond. 





The mean house price 
20030910 

Carol pose la question :
Question: I have to find the mean from the following example: Price Range £000  No of Houses  55 and under 60  3  60 and under 65  6  65 and under 70  13  70 and under 80  21  80 and under 100  15  100 and under 130  7  130 upwards  1  I know when calculating the mean you use the mid points of the classes, but how does this work for the 130 upwards class? Also, does this still work given the difference in the classes (ie. 1st class is 5, 5th class is 20, etc). Any help to get me started would be greatly appreciated. Penny Nom lui répond. 





Converting from base 10 to base 5 
20030910 

Susy pose la question :
My son, who is 9 in grade 5 has been asked to convert base 10 numerals into base 5. His first question of: 24(10) he has calculated to be 4x5 + 4x1 = 44 (5) The next question however is the tricky one.Ý We know the answer is supposed to be 100 but we find it difficult to get this in the way he understands it. 25 (10) = _________________ 100 (5) Can you help us figure out how we reach the answer. Claude Tardif and Penny Nom lui répond. 





How high does the sequence of numbers go 
20030907 

Shayna pose la question : My quetion is "How high to the sequence of numbers go"? e.g. one, ten, hundred, thousand, million, billion, trillion, and from there is my queston. Penny Nom lui répond. 





Making a square 
20030907 

A student pose la question : if I am given any number (say 80 for example), how may I determine the smallest whole number integer which when multipled by it will yield a square number ? In other words if I express this as: 80Ý*ÝnÝ=ÝsquareÝnumber, what is the least value of n which will yield a square. Penny Nom lui répond. 





Consecutive integers 
20030907 

Amy pose la question : I was wondering if there was a proper way to write the solution to a problem requiring consecutive integers? Is it okay to write the solution as 5,4,3,2,1 or must it be written as 1,2,3,4,5? Penny Nom lui répond. 





Order of operations 
20030907 

Brian pose la question :
It has to do with the 4 rules of operations, Parentheses first before operations outside/evaluate all exponential expressions/all multiplication and divisions/then all additions and subtractions. Who made these rules and when did they make them,,, I know its somewhat of an unorthadox question but I must know. I would really appreciate it. Penny Nom lui répond. 





7,473,000,000 divided by 52000 
20030906 

A student pose la question : I am having trouble with a question. 7,473,000,000 divided by 52000. Our calculater gets 147311.5385. I come up with 143711.53846, and then the number starts to repeat itself Penny Nom lui répond. 





Can 2 vertical planes intersect? 
20030906 

Erin pose la question : My question is can 2 vertical planes intersect? Penny Nom lui répond. 





One million seconds 
20030904 

Vince pose la question : If you can write a number each second for one million seconds, how many hours would it take? Penny Nom lui répond. 





Four digit combinations 
20030904 

Emma pose la question : I seriously need to find out all the four digit combinations from 0 to 9!!! My name Is Emma Dibitt and I'm going into 8th grade and I'm a student!!! Penny Nom lui répond. 





Grooming the king's horses 
20030904 

Janelle pose la question : the stable boy had 90% of the kings horses groomed.the next day the king acquired 25% more horses. Now there was 105 horses not prepared for the kings men. How many horses did the king originally have? Penny Nom lui répond. 





A 16 foot ladder 
20030904 

Kelly pose la question : Two buildings are separated by a threefoot alleyway. Fatima wants to use a 16 foot ladder to reach a window in the wall of one of these buildings. If she places the foot of the ladder against the base of the other building, how far up the wall will the top of the ladder reach?? Penny Nom lui répond. 





One percent of a billion 
20030904 

Charles pose la question : What is one percent of one billion? Penny Nom lui répond. 





Positive, negative and zero 
20030904 

Brian pose la question : Can the Value of zero be positive or can it be negative or can it be both. Penny Nom lui répond. 





The game of 24 
20030903 

A student pose la question : We have a game where four numbers must equal 24 using addition, subtraction, multiplication and/or division.Ý I am stuck on the following four numbers  12, 24, 9 and 17. Penny Nom lui répond. 





A boat travels 12 km upstream... 
20030903 

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. 





Why percentage? 
20030903 

Vicky pose la question : My cousin aske me a question about the use of percentages and I'm not sure how to answer it. He wants to know why when there is a sale in a shop we use percentages and not fractions or decimals. Penny Nom lui répond. 





Percentage markup 
20030903 

Virginia pose la question :
I am confused and hope you can help. I have looked high and low for a "chart" persay to go by when I am having to calculate markup percentages. Example if I have a List price of $1838.00 and my cost is $955.76 and I want to mark it up 30%. My colleage says it should be divided by .7 I don't understand how he arrives at .7 from 30 percent. Claude Tardif lui répond. 





Profit margin 
20030903 

Chet pose la question :
My salesman calculates a customers profit margin by dividing what the customer paid by what he sells for, then subtracting that answer from 1. For example a customer sells a product for $15. He bought it for $10. 15/10=.66 Subtract that from 1 and get a profit % of 33% Here's my question: If I want to figure what a reseller will sell a product for if he wants 40% margin(by the technique above), what formula do I use? Let's say I want to sell a product for 8.50, and I want the reseller to make 40% Penny Nom lui répond. 





Two row arrays 
20030903 

Madalyn pose la question : My question is, what are #'s that can not be arranged in two row arrays called? Penny Nom lui répond. 





A helicopter rises vertically 
20030902 

Kate pose la question : A helicopter rises vertically and t seconds after leaving hte ground its velocity is given in feet per second by v(t) = 8t + 40 / (t+2)^{2} How far above the ground will the helicopter be after 3 seconds? Penny Nom lui répond. 





Water in a tank 
20030902 

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 
20030902 

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 PT^{2} = AP x BP. Dieter Ruoff and Penny Nom lui répond. 





The units digit of 57 to the 28th power 
20030901 

Maria pose la question :
If 57 is raised to the 28th power, what must be the units digit in the result? If you raise 7 to the 500th power, what is the numeral that will appear in the units digit position? Penny Nom lui répond. 





A 6 team schedule 
20030831 

A scheduler pose la question : I saw that someone put on your web site a team schedule and you helped them figure it out.Ý I have 6 teams that want to play each other once, and believe it or not, I cannot figure it out. Penny Nom lui répond. 





20% of 40% of 500 
20030831 

A student pose la question : What is 20% of 40% of 500? Penny Nom lui répond. 
