







deux wagons 
20130405 

Cyril pose la question : Bonjour,
je suis confronté à un problème dont je n'arrive pas à trouver la solution.
Le voici: "Deux wagons de masses 30 tonnes et 60 tonnes entrent en collision sur une voie ferrée droite horizontale, ne déraillent pas et restent collés ensemble après le choc.
Juste après la collision, ils roulent ensemble à 10 km/h vers le nord. Sachant que le wagon léger roulait à 20km/h vers le nord avant la collision, la vitesse du wagon lourd avant la collision = ?"
Je pense qu'il faut employer la formule de la quantité de mouvement "p=mv" mais je ne sais pas comment m'y prendre...
Merci d'avance pour votre aide!
Cyril Biselx Claude Tardif lui répond. 





une écriture plus simple des expressions 
20110113 

jessie pose la question :
trouver une écriture plus simple des expressions suivantes sachant que : x + y = 3 et x  y =2
A=x1+y+2 B=x1+y2
C=x+1+y+2 C=x+1+y2 Claude Tardif lui répond. 





Division 
20100310 

lucas pose la question : bonjour je suis eleve de 6 eme
je bloque sur ce petit probleme
Nat a fait une division,elle ecrit
4568=23*198,608+reste
que vaut ce reste?
merci d'avance
lucas Claude Tardif lui répond. 





Un système de plusieurs équations et plusieurs inconnues 
20090122 

Cédrick pose la question : J'ai un problème écrit à résoudre estce que vous pouvez m'aider ?
Le premier est le tiers de la somme des deux autres.
La somme du premier et du deuxième est 13.
Le produit du deuxième et du troisième est 56.
Réponse: Le premier nombre est___________________
Le deuxième nombre est _________________
Le troisième nombre est _________________
PierreLouis Gagnon, Antoine Letarte at Claude Tardif lui répond. 





Je voulais savoir d'où provient le signe # ?! 
20080117 

Dimitri pose la question : Je voulais savoir d'où provient le signe # ?!
On l'appelle diez, sur les téléphones surtout, mais j'aimerai savoir plus précisément à quoi sert ce signe (autre que sur nos appareils) !
Et pourquoi, en anglais, s'il est placé avant un chiffre, on dit 'number' (par exemple #1, 'Number one').
Son origine m'interesse tout autant que son utilité ! Claude Tardif lui répond. 





Progression arithmétique 
20080108 

parrot pose la question : Bonjour je suis en 6ème et j'ai besoin d'aide pour un problème de math.
Donc voila mon problème :
Un renard a mangé 100 grains de raisins pendant une periode de 5 jours.
Chaque jour, il a mangé six grains le plus que le jour précédent.
Quel est le nombre de grains mangés le premier jour ? Claude Tardif lui répond. 





Le symbole ∈ epsilon 
20071010 

Cora pose la question : Je veux aider ma fille avec ses devoirs. C'est quoi le symbole qui semble un
E, mais c'est un demicircle? ie:X ∈ N Claude Tardif lui répond. 





les données sont inconsistantes 
20071003 

Mikee pose la question : Bonjour,
Je me casse la tete depuis ce matin et la je donne ma langue au chat.
Je n'arrive pas a resoudre ce probleme.
J'ai 30 agents qui appellent dans la journee et realisent 322 questionnaires (long+court) telephonique avec une duree moyenne de conversation 294 secondes.
dans ces 322 qestionnaires :
ils realisent 313 questionnaires Long avec une duree moyenne de 317 secondes.
ils realisent 9 questionnaires Court avec une duree moyenne X.
je cherche X.
((Interviews réalisées*Durée moyenne de conversation)(Interviews réalisées avec la question Q2*Durée moyenne de conversation avec la question Q2))/(Interviews réaliséesInterviews réalisées avec question Q2)=Durée moyenne de conversation sans la question Q2
Q2=questionnaire Long Claude Tardif lui répond. 





Illusion géométrique 
20070404 

Dominique pose la question : Je n'arrive pas expliquer la modofocation de surface. Claude Tardif lui répond. 





sup {sin n, n est un entier } 
20061217 

Madi pose la question : sup {sin n, n est un entier } Claude Tardif lui répond. 





probleme sin cos 
20060219 

Thibault pose la question : mon probleme commence par: f(x)=sinx (sinx+1)+ cos²x
donc en le dévellopant on trouve: f(x)= sin²x + sinx + cos²x
et apres ce que je ne comprend pas est que par la suite on trouve: f(x)= 1+sinx
qu'estce qui fait que l'on trouve ce resultat?? Claude Tardif lui répond. 





des conversions de bases différentes 
20030104 

Christian pose la question : Je cherche désespérément la (les) règle(s) pour réussir des conversions de bases différentes : de base x vers base y. Claude Tardif lui répond. 





100 centimètres 
20021113 

Un élève pose la question : je voudrais savoir la contenance de 100 centimètres cube en litre? Diane Hanson lui répond. 





Conversion de m2 en cm2 
20020310 

Carole et Francis pose la question : Mon enfant est en 6ième année, il avait le problème suivant à faire dans un test: Trouve l'aire d'un rectangle mesurant 9 m par 4 m; donne ta réponse en m^{2} et en cm^{2}? Voici la solution de mon fils: 9m x 4m = 36m^{2} 9m = 900cm 4m = 400cm donc 900cm x 400cm = 360 000cm^{2} D'après moi sa réponse est bonne, j'aimerais avoir une confirmation puisque l'enseignante lui dit qu'il y a erreur. Claude Tardif lui répond. 





l'équation d'une rotation dans un graphique cartésien 
20011114 

Ghaith pose la question : je d6sir que vous me rafraichissez un peu la mémoire s.v.p. j'aimerai savoir l'équation d'une rotation dans un graphique cartésien merci Claude Tardif lui répond. 





Les tableaux de conversions 
20010503 

JeanJacques pose la question : Sur quel site est il possible de trouver tous les tableaux de conversions de mètres,kg,litre,m2,m3 Quelle est la relation entre les m^{3} et les litres 1 m^{3} = 1000 litres = 1000 kg? Claude Tardif lui répond. 





Calculer la hauteur de chute de cette pierre 
20001216 

Marcus pose la question : Une pierre tombe au fond d'un puit, à 5 secondes on entend un son (de la pierre). Calculer la hauteur de chute de cette pierre en tenant compte de la vitesse du son = 340m.s^{1} Il faut savoir que pour la chute libre v= g.t ; h = 1/2 g.t^{2} ; v = 2g.h g intensité du champs de pesanteur = 10 ; h hauteur de chute. Claude tardif lui répond. 





la dimension fractale 
20000501 

François RIVOIRE, Julien CHOLLET et Alexandre DECOSTER pose la question : nous sommes étudiants en première année MPSI en école d'ingénieur ISEN ( Institut supérieur d'électronique du Nord ). Nous avons choisi les FRACTALES ( ou plus précisément sur la dimension fractale et topologique ainsi que sur les suites logistiques) comme sujet de TIPE; seraitil possible que vous nous envoyez des démonstrations mathématiques ou des conseils car jusqu'ici nous avons eût beaucoup de mal à trouver des démonstrations se rapportant à ce sujet, Claude Tardif lui répond. 





Calculating the area (acreage) of a four sided lot 
20070718 

A property owner pose la question : I have a real estate property and the lot size is something I need to find out. I know the lengths of the four sides, but it isn't a rectangle, it is an odd shape. How do I find the acreage? Stephen La Rocque lui répond. 





Lot size / acreage (more than three sides) 
20070511 

Martha pose la question : What is the lot size of the following dimensions equivalent to acre.
141.85 x 52.55 x 217.63 x 38.89 x 68.08 Penny Nom and Stephen La Rocque lui répond. 





A 1.4 acre square 
20160628 

Jamie pose la question : Dear Faithfullness,
I was previously to be purchasing a square 1 acre plot, which I believe was to have 209feet, 4 sides perimeter.
How big would a 1.4 acre site be?
In sq feet length ie original 209ft + (the adeed 0.4) Penny Nom lui répond. 





Simultaneous equations 
20160625 

sena pose la question : 2x/3+3y/2=1
4x5y=22
simultaneous equation Penny Nom lui répond. 





The lateral side length of a cone 
20160605 

Diane pose la question : Question is find the lateral side length of a right cone with area of 372 sq. cm and base circle radius of 9 cm. Penny Nom lui répond. 





The area of a 4sided lot 
20160525 

prasad pose la question : How to find area of a land whose sides are 41ft,33ft,32.3ft and 33.2 ft. Pl give me the formula and proof. Penny Nom lui répond. 





A trough with a triangular cross section 
20160521 

Clarice pose la question : A trough having an equilateral triangle end sections has sides equal to 0.4 m and 7m long.what is the volume of the liquid in the container if the depth of the water is one half the depth of the trough? Penny Nom lui répond. 





The volume of a truncated rectangular pyramidal pond 
20160513 

Paul pose la question : How do you calculate a partially filled truncated rectangular pyramid if you always know the bottom rectangle, the maximum height top rectangle perimeter, but have a varying height. Similar to filling up a pond you know the current height and dimensions at the max rectangle how do you calculate it half full i.e. 10x30 outside perimeter with a 2x8 base and a max height of 6ft how do you calculate it at 3ft without remeasuring the top perimeter.
Thanks,
Paul Penny Nom lui répond. 





A pair of equations with fractions 
20160511 

tiya pose la question : hello, i want to know how to solve this question.
m/6+2n/3=6
m/10=2n/5=2 Penny Nom lui répond. 





At what time will Sara catch up with Jake? 
20160507 

Laura pose la question : At 11:00 a.m., Jake started driving along a highway at constant speed of 50 miles per hour. A quarter of an hour later, Sara started driving along the same highway in the same direction as Jake at the constant speed of 65 miles per hour. At what time will Sara catch up with Jake? Penny Nom lui répond. 





A six digit code 
20160506 

Ralph pose la question : How many combinations are possible if a "safe" has four buttons and you can use a six digit code? (these are just single press buttons..)For example, this could be one possible combination: Button 4 Button 1 Button 1 Button 3 Button 2 Button 4. Thanks! Penny Nom lui répond. 





Covering a site with 6 inches of rock 
20160426 

Carla pose la question : if a pump house that measures 20'x16' sits in the middle of a site that is 50'x60' and you apply crushed rock to the site at depth of 6", how many yards will you need to haul? Penny Nom lui répond. 





External and interior angles of a regular polygon 
20160419 

pearl pose la question : a polygon has n sides.The exterior angle is 8 times the interior angle
find the value of the interior angle
find the value of n Penny Nom lui répond. 





Conversion of an equation 
20160411 

Marie pose la question : How to you convert the equation of a line from xintercept form
(y=(xx1)(xx2)) to general form (y=ax^2+bx+c) if it involves square
roots?
For example:
Convert this equation to general form: y=(x+the square root of 5)^2
Thanks for the help! Penny Nom lui répond. 





Filling a hole with 14 tons of rock 
20160408 

Barry pose la question : If I had 14 tons of inch and one half sized aggregate rock, how large of a square or rectangular shaped hole would I need to hold that amount? Penny Nom lui répond. 





The remainder theorem 
20160327 

Pratyasha pose la question : A quadratic polynomial when divide by x+2 leaves a remainder of 1 and when divided by x1 leaves a remainder of 4. What will be the remainder if it is divided by (x+2)(x1)? Penny Nom lui répond. 





Polynomial division 
20160325 

Ashley pose la question : (4x4+6x^3x^2)/(3x2)
The instructions say to "perform the division". Penny Nom lui répond. 





A rotating schedule for a softball team 
20160325 

Caroline pose la question : I couldn't find a similar question, hopefully there isn't one!
I have a softball team of 18 people (7 girls and 11 boys), but am limiting each game to 13 players (6 girls and 7 boys). The season is 10 games long. How do I create a rotating schedule which allows members to play evenly? I tried separating the boys and girls to create rotation for each but I got confused. Some are unable to attend all games but for the simplicity of a rotation schedule can you please help? Robert Dawson and Victoria West lui répond. 





The sides of a triangle 
20160315 

Hitarth pose la question : Why we cannot construct a triangle ofngiven sides 5cm,5cm and 10cm? Penny Nom lui répond. 





Can you construct a regular 21gon? 
20160308 

Peter pose la question : hi, i know that if i use a compass to draw a circle, i can use the same setting to mark 6 intervals along the circle circumference, how would i go about marking out 21 equally spaced points around the circumference?
if there an online calculator i can us, or some other interesting trick?
tia
peter Robert Dawson lui répond. 





A geometric progression 
20160303 

Pauline pose la question : A woman measures the height of her child at birth and at monthly intervals afterwards.The child's height increases by 5% per month. Find the number of measurements she has made before the child's height is twice what it was at birth Penny Nom lui répond. 





Solve for x and y 
20160227 

ntshidi pose la question : Y=1/2x+4and1/4x6 Penny Nom lui répond. 





How can I express Sin 4A in term of Sin A? 
20160222 

Odukoya pose la question : How can I express Sin 4A in term of Sin A? Penny Nom lui répond. 





A bonus of 8% of sales 
20160222 

Barghavi pose la question : A man earns $325 per week plus an additional 8% on any sales over $500.
If he makes $6,250 in sales, how much money in total does he earn that week?
thank you! Penny Nom lui répond. 





0/0 
20160214 

Noni pose la question : Q. 0÷0=1 Why it is wrong when 4÷4=1; 3÷3=1; 2÷2=1: 1÷1=1 ? Penny Nom lui répond. 





Two equations in two unknowns 
20160213 

Anumba pose la question : 4x + 2y = 4
7x  y = 11 Penny Nom lui répond. 





The midpoints of the sides of a quadrilateral 
20160205 

Andrea pose la question : The segments, joining, in order the midpoints of consecutive sides of a quadrilateral form a parallelogram. Penny Nom lui répond. 





The height of a triangle 
20160203 

Brooklyn pose la question : How do I figure out the height of a triangle when it only tells me the base of he triangle? And vice versa. Penny Nom lui répond. 





Division base 5 
20160201 

Jenalee pose la question : I am having problems with a dividing bases question. I reviewed two that I could find in the database and tried the question as shown but I am still getting the wrong answer.
My question is 32\24043 to the base of 5 for both. Penny Nom lui répond. 





Simplify 
20160201 

Sabira pose la question : Simplify step by step
5x/8 + 7y/18 = 6 Penny Nom lui répond. 





A system of linear equations 
20160124 

kareem pose la question : my name is kareem
and i am a student i have a math puzzle and i tried to solved it but it always have same mistake
xy=9
x+z=12
zn=14
y+n=2 Penny Nom lui répond. 





The volume of a silo 
20160118 

Clinton pose la question : Can you show me how to calculate the ground corn capacity in a steel silos of 10' x 10' high and 10' x 20' high and 10' x 24' high and 10' x 28' high Penny Nom lui répond. 





The perimeter of a one quarter acre square 
20160115 

Kerry pose la question : If you have a perfect square that is one quarter of an acre what are the length of the sides and how do you arrive at the solution? thank you, Kerry. Penny Nom lui répond. 





A sequence 
20160105 

Mia pose la question : the next three terms in each sequence. 0.4, 0.54, 0.68, 0.82, Penny Nom lui répond. 





Constructing simultaneous linear equations 
20151228 

Deborah pose la question : Linda thinks of a twodigit number. The sum of the digits is 8. If she reverses the digits, the new number is 36 greater than her original number. What was Linda's original number?
Thank you! Penny Nom lui répond. 





Converting a fraction to a percent 
20151222 

Sharon pose la question : How do you turn a fraction into a percentage? I'm beyond confused with this. Even though I think of myself as a good math student doing 8th grade math at a young age, this just makes me want to scream! I get the way you turn 1/4 into 25%, but when it comes to something like 7/9 = ? I just can't figure out the answer. Penny Nom lui répond. 





The angles of a triangle 
20151217 

Faith pose la question : Does the measure of angle determine the length of its side? For example two angles are congruent then the sides are also congruent because from my understanding the angle determine the shape of triangle. Penny Nom lui répond. 





Sierpinski Pyramid 
20151214 

victor pose la question : Is a tetrix (a Sirpienski Pyramid/Tetrahedron) its own hyperplane?...alternatively, is it a hyperplane? Robert Dawson lui répond. 





Linear equations in two variables 
20151213 

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





Travelling in opposite directions 
20151206 

Roselyn pose la question : Jenny and Mark commute to work, travelling in opposite directions. Jenny leaves the house at 8 AM, and averages 35 kph. Mark leaves at 8:15 AM, and averages 40 kph.At what time will they be 40 kilometers apart? Penny Nom lui répond. 





Dividing by a fraction 
20151121 

Jennifer pose la question :
Question from Jennifer, a student:
I want to know how to get the right answer for this math problem, dividing a fraction in to a whole number , example 3/8 using the whole number 6? Thanks Penny Nom lui répond. 





A volume in cubic yards 
20151112 

James pose la question : The first formula for figuring cubic yards of concrete need is length in feet, times width in feet, times depth in actual inches, divided by 320. Such as, 150x 50 feet x 4inches divided by 320 = cubic yards. How and why does this formula work? Penny Nom lui répond. 





Simplify 3(x7) 
20151021 

geraldine pose la question : simplify: 3(x7) Penny Nom lui répond. 





A six team league to play a 20 game schedule 
20151019 

Kelly pose la question : Hi there. Some of your posts are close, but my problem is evening out the home
and away games. We have 6 teams in our league and we are going to play a 20
game schedule, playing everyone 4 times. We will play Fridays and Saturdays,
each weekend. Of course the ideal would be to have each team have a home and
an away game each weekend, but I realize that is impossible, but I would like it as
close as possible. Any help would be much appreciated!! We also were considering
opening with a home and away  Friday then Saturday with the same teams. Then
carrying on with playing everyone else and then possibly finishing up with the same
home and home Victoria West lui répond. 





Six teams playing five games 
20151018 

Aidan pose la question : I have six teams that will be playing five games.
I want each team to play each game once and each team to play each other team once.
Is this possible or should I add an extra round and let some teams play each other twice? Victoria West lui répond. 





The dimensions of a rectangle 
20150925 

Erick pose la question : A rectangular strip of land has a perimeter of 124meters and an area of 385 square meters. Find its possible dimensions Penny Nom lui répond. 





A 6person team that has 9 players 
20150921 

Sheri pose la question : I am organizing a 6person team that has 9 players. How do I schedule them fairly over a 9 week league? Victoria West lui répond. 





Seven switches with 3 stages each 
20150915 

jeff pose la question : We are trying to solve a combination problem. If I have 7 things that can be in 3 states (say on/partially on/off), and all 7 have to a state. How many different combinations can there be? It doesn't seem like we should treat it as 21 independent things, but not sure how to break the problem apart. Penny Nom lui répond. 





Division and units 
20150908 

Kenneth pose la question : Hello:
Would there be a reason to divide a number without units by another number with units?
Here is an example:
35 divided by $5.00 or 35/$5.00
The answer cannot have units ($) because $5 X 7 does not equal 35 but instead $35.00.
$35.00 divided by 5 or ($35.00/5) and $35 divided by $5.00 or ($35.00/$5.00) make more sense.
I thank you for your reply. Robert Dawson lui répond. 





Factor x^2 + y^2 
20150826 

Jerome pose la question : Factor: x^2+y^2 Penny Nom lui répond. 





Four equations in 3 unknowns 
20150823 

damien pose la question : solve:
S x U  T = 44
T  U x S = 36
U + T  S = 7
U x U / S = 4 Penny Nom lui répond. 





The length of a shadow 
20150801 

maaz pose la question : Hello
I am having trouble with this question:
Lizzie, who is 6 feet tall, stands in her driveway at night, exactly
24 feet from the base of a spotlight, and casts a shadow that is 12
feet long if her friend Hannah who is 5 feet tall decides to stand
next to lizzie how long will her shadow be? Penny Nom lui répond. 





1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 x 0 + 1 = ? 
20150618 

Sharon pose la question : 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 x 0 + 1 = ?
I got 1 as my answer despite BODMAS making it 12 because logic tells
me I ought to place brackets around the first set of repeated addition. Could you
please clarify this for me? Thank you 😊 Harley Weston lui répond. 





An octagonal frame around a pool 
20150517 

James pose la question : I have a 20' pool and need to put a frame around it using 2by 4 what r the lengths and angle cuts Penny Nom lui répond. 





An angle of depression problem 
20150514 

haxir pose la question : find the height of the balloon directly above a town if the measure of angle of depression of another town 5km from the first town is 20°!6` Penny Nom lui répond. 





Repeated decimals 
20150509 

Vir pose la question : Years ago I (re?)discovered 'cyclic division'. For example: if you arrange the number along a circle and put the number 142857 at the centre
all the numbers taken cyclically, starting with 1, are fully divisible by 37. Whatever the starting point of this number, it remains fully divisible by 37.
what is more, the number can be formed by taking the digits clockwise as well as anticlockwise..This I call "full cyclic divisibility". In many cases, only clockwise cyclic divisibility is possible. But I have not come across a case where ONLY anticlockwise divisibility occurs. Thus clockwise cyclic divisibility seems to be favoured. Could this be construed as a sign of chirality in mathematics?.. Chris Fisher lui répond. 





The number of possible musical notes using an nkey instrument 
20150504 

Farihin pose la question : Lets say that i have keys, and each key is for notes of a musical instrument,
So i wanted to find out the number of notes i can get for a certain number keys,
of course in the form of an equation. Notes can use as many keys, it can use 1, or 2, or 3, or even 100.
Notes in real life is not as such, but ignore reality.
I tried doing this but i can't seem to find a formula for it.
For example, i have 4 keys, say A, B, C, and D.
so, for notes that uses one key are 4, which is A, B, C, and D themselves.
for notes that uses two keys are 6,
AB, AC, AD, BC, BD and CD.
for notes that uses three keys are 4,
ABC, ABD, ACD and BCD.
lastly for notes that uses all four keys is 1, ABCD.
So, the total will be 4+6+4+1=15#
The nth term for the first equation is n, the second is [(n^2)n]/2
the third and the fourth, i don't know but the final answer should be like,
n + [(n^2)n]/2 + [3rd] + [4th]
Sorry for the long question though... Penny Nom lui répond. 





13 games, 3 possible outcomes 
20150501 

Kennedy pose la question : Hello, hope it finds you well.
Am not that good with numbers, can you please help me get all the possible outcomes of 13 games, with a home win, draw or an away win as three possible results for each of the 13 games.
Thanks in advance Penny Nom lui répond. 





The method of elimination 
20150501 

oreanna pose la question :
Question from oreanna, a student:
How do u solve 2x+9y=3
7x4y=25 in elimination Penny Nom lui répond. 





Expand and Simplify (3x+5)(5x9) 
20150423 

chloe pose la question : Expand and Simplify (3x+5)(5x9) Penny Nom lui répond. 





How many boats total are in the marina? 
20150415 

Carla pose la question : In a marina, 3/4 of the boats are white, of the remainder 4/7 are blue, the rest are red. There are 9 red boats. How many boats total are in the marina? My answer is 84 because if 1/4 of the boats are divided into sevenths, that makes the whole marina a 28 part item. 3/28 are red so 84 is the total number of boats. My child thinks I am wrong. Penny Nom lui répond. 





Two airplanes 
20150414 

john pose la question : two planes leave an airport at the same time, one going northwest (N35*W)at 400 mph and the other going east at 332 mph. How far apart are the planes after 4 hours to the nearest mile? Penny Nom lui répond. 





Some nondecreasing sequences 
20150413 

Sky pose la question : Hi I'm a Student and i'll try my best to state the problem perfectly.
The number of nondecreasing sequences of size at least 1 and at most N,
such that each element of the sequence lies between L and R, both inclusive.
Eg: N=1 L=4 R=5
ans= 2. [{4},{5}]
N=3 L=4 R=6
ans= 19. [{4},{5},{6},{4,4},{4,5},{4,6},{5,5},{5,6},{6,6}
{4,4,4},{4,4,5},{4,4,6},{4,5,5},{4,5,6},{4,6,6},{5,5,5},{5,5,6},{5,6,6}
,{6,6,6}] Claude Tardif lui répond. 





A word problem with fractions 
20150409 

Lorraine pose la question : If the numerator of a certain fraction is doubled and the denominator is increased by 1, the fraction becomes 1/2.
If the numerator of the original faction is squared and the denominator is decreased by 2, the fraction becomes equal to 1.
Let x be the numerator and let y be the denominator of the original fraction.
Write down two simultaneous equation in x and y.
Solve these equations to find two possible values for the given fraction. Penny Nom lui répond. 





The weight of a steel block 
20150404 

Mark pose la question : the weight of a steel cube 37 inches X 28 inches X 7 inches Penny Nom lui répond. 





The side length of a gazebo 
20150314 

Dennie pose la question : From middle of side to middle of opposite is 14'6". What is the length of the side? Penny Nom lui répond. 





Commission 
20150313 

Rose pose la question : A shopkeeper receives 12.5% (12 1/2 %) commission on the sale of books from
the publisher. In a certain month,he receives a commission of rs.250 from the
publisher. How much was his sale for that particular month?? Penny Nom lui répond. 





Angles of elevation and depression 
20150308 

Timmy pose la question : Joel is walking down a street and sees a 115 ft tall building in front of him. He stops 190 feet from the base of the building at the tip of the building's shadow. Round answers to three decimal places.
A. If there was a piece of rope from the top of the building to Joel, how long would it be?
B. What is the angle of elevation from Joel to the top of the building?
C. Margaret says that she could find the angle of depression from the top of the building to Joel by subtracting the angle of elevation from 90°. Is she correct? Explain. Penny Nom lui répond. 





The definition of percent ( % ) 
20150307 

Kenneth pose la question : Hello:
I saw this definition online from the Free Dictionary (The Free Dictionary.com) regarding the definition of percent (%):
"Noun 1. a percent sign  a sign (`%') used to indicate that the number preceding it should be understood as a proportion multiplied by 100."
What is this "proportion" multiplied by 100?
When I think of a proportion, I think of a/b = c/d. How can a number preceding the percent sign be understood as a proportion X 100?
I thank you for your reply! Chris Fisher and Claude Tardif lui répond. 





A man is standing on top of a building 
20150306 

kiki pose la question : a man of height 1.5m standing on top of a building of height 48.5m views another building across the square. he observe that the angle of depression of the bottom of the building is 40 degrees and the angle of depression of the top of the building is 5 degrees. Both buildings stand on the same level
a) calculate the distance of the man from the base of the building across the square measured along the line of sight Penny Nom lui répond. 





Two consecutive positive integers 
20150301 

meha pose la question : Find two consecutive positive integers , sum of whose squares is 365. Penny Nom lui répond. 





Two equations with fractions 
20150226 

Pulane pose la question : Hi math centre I've been trying to solve these equations for days now please help
(6/x)(1/y)=4
(9/x)+1=(2/y)
Please help me solve them simultaneously
Thank you Penny Nom lui répond. 





3 over "x" plus 5 
20150223 

Kenny pose la question : 3 over "x" plus 5. I don't know this is either a polynomial and if so how would you define it. Harley Weston lui répond. 





Two equations 
20150216 

nigel pose la question : 2x+1/2y=1
6x3/2y=21 Penny Nom lui répond. 





A stone is dropped in a lake 
20150214 

Wendy pose la question :
Hi, I have problems solving this problem. We didn't exactly go over these kind of problems and the book doesn't have an example either. Thank you for your help!
A stone is dropped in a lake, creating a circular ripple that travels outward at a speed of 80 cm/s.
(a) Find a function g that models the radius as a function of time t.
g(t) =
(b) Find a function f that models the area of the circle as a function of the radius r.
f(r) =
(c) Find f compose g.
f compose g = Penny Nom lui répond. 





The volume of Lake Utah 
20150129 

Hannan pose la question : Lake Utah has a surface area of 3,846 square miles and an average depth of 10.5 feet. In cubic miles, how much water does it hold?
How would you approach this question? Where would you start? Robert Dawson and Penny Nom lui répond. 





128/(16)/(2) 
20150128 

jackie pose la question : 128/(16)/(2) I was wondering if you can show me how to work this question out Harley Weston lui répond. 





Is a square a trapezoid? 
20150126 

Katie pose la question : Can a trapezoid sometimes be a square? Penny Nom lui répond. 





sin x = cos x 
20150123 

Mubashir pose la question : there are two curves y=sinx and y=cosx intersecting at point where x is less than 90 and greater than 0.to find the point I made a equation sinx=cosx
but donot know what to do further .please help me by solving this equation sinx=cosx
also tell me that have you solved this equation by reference to the graph or by other means please do elaborate your solution in your answer. Penny Nom lui répond. 





The height of a building 
20150120 

Emily pose la question : A man 2m high observes the angle of elevation to the top of the building to be 70 degrees. And the angle of depression to the bottom of the building to be 19 degrees. How tall is the building? Robert Dawson lui répond. 





Pumping water from a borehole 
20150118 

patience pose la question : An empty tank for storing water from a borehole has a volume of 480 cubic metres. If it is filled by a pump that pumps water at a rate of 16 litres per second, how many hours will it take the pump to fill this tank please show all calculations Penny Nom lui répond. 





Mutually prime composite numbers 
20150109 

nivedita pose la question : Two composite number that is mutually prime? Penny Nom lui répond. 





Missing digits in a phone number 
20150107 

Janelle pose la question : I had a friend try and play a game on me, regarding phone numbers, so I only know the area code , and the last four digits of the phone number. Which means, there are 3 digits that I need to figure out all the possibilities to. Penny Nom lui répond. 





A silo is composed of a hemisphere and a cylinder 
20150103 

Ami pose la question : A silo is composed of a hemisphere and a cylinder. The total height for the silo is 20m and the diameter of the silo is 8m. What is the volume of the silo to the nearest cubic meter? Penny Nom lui répond. 





1 + 2 + 3 + ... + (2n  1) 
20150101 

Brian pose la question : Hi Maths Central
My wife presented me with a query which may have a simple answer, but one that I can’t deduce or explain.
Take the string of numbers, n=1,2,3,4,5…
It seems that n(2n1) = Sum((1…..(2n1))
e.g. for n=5, both 5 x 9 and Sum(1….9) equal 45, and so on for other values of n.
Could you please provide an explanation? Does it have an underlying reason and a name?
Look forward to your response.
Brian Penny Nom lui répond. 





Rates, percentages and units 
20141230 

Kenneth pose la question : Hello:
If percentages have no units, why are some percentages called rates, as in interest rate, or
perhaps a tax rate of 7% as an example? A rate has units of different quantities.
I thank you for your reply. Robert Dawson lui répond. 





Remainder 
20141208 

Muqadasah pose la question : A number, when divided by136, leaves remainder 36. If the same number is divided by 17, what will be the remainder? Penny Nom lui répond. 





How do you change a decimal to a ratio? 
20141129 

Esmeralda pose la question : How do you change a decimal to a ratio? Express the decimal 0.2 as a ratio. Penny Nom lui répond. 





An arithmetic progression 
20141119 

Gbenga pose la question : In an A.P the difference between 8th and 4th term is 20. The 8th term is 1\2 times the 4th term . Find arithmetic progression.. Penny Nom lui répond. 





How many square feet in 10 gallons of liquid at 1/4 in thick? 
20141114 

Rich pose la question : How many square feet in 10 gallons of liquid at 1/4 in thick Penny Nom lui répond. 





1/6k=11 
20141113 

Marty pose la question : Using the balance method, what is the answer to 1/6k=11, trying to find what k equals. Thanks Penny Nom lui répond. 





The density of sea sand 
20141102 

Lenny pose la question : Hi There,
I need to find out the the density of sea sand to convert one metric ton to cubic
meter as I am submitting for a tender which is in cubic meter but the requirement
is in metric ton. I searched through the web site but no density of sea sand is given
though there is specific Gravity of dry sand is available. I was given a density of
1.6 to work with. If that is true am I right to say that 1 cubic meter of sea sand is
equivalent to 1.6 metric ton? Please help as I am getting confused with what I am
able to find out on the web.
Thanks much in advance
Rgds
Lenny Penny Nom lui répond. 





A linear system 
20141014 

pheter pose la question : 4/x  1/y = 3 .... equation (1)
6/x  2/y = 5 .... equation (2) Penny Nom lui répond. 





A fact family containing 4, 4 and 16 
20141014 

Leslie pose la question : I am helping my son and the question is 4,4,16 in fact family what does that mean Penny Nom lui répond. 





Building an 8 sided box 
20141014 

Michael pose la question : I want to build an 8 sided box. The North, East, South, and West sides I want them to be 4 feet in length.
The NE, SE, SW, and NW sides I want to be 2 feet in length. What angles do I need to cut my angles.
Thanks Michael Penny Nom lui répond. 





Sieve of Eratosthenes 
20141003 

Hope pose la question : using Sieve of Eratosthenes to determine for in instance prime numbers between 1 to 200, to what nth number should i stop?, 4th, which is 11 or what? Robert Dawson lui répond. 





Trig functions and the unit circle 
20141002 

Jake pose la question : I was wondering what conclusions can be drawn about the trigonometric functions and how they work about the circle. Can you also please give me an explanation for it? Thank you. Penny Nom lui répond. 





Division in base 3 
20140930 

Nnubia pose la question : 1021 in base 3 divided by 2 in base 3 Penny Nom lui répond. 





A rectangle and a triangle 
20140927 

rajesh pose la question : The perimeter of a rectangle is equal to the perimeter of a rightangled triangle of height 12 cm if the base of the triangle is equal to the breadth of the rectangle, what is the length of the rectangle? Penny Nom lui répond. 





Two equations in x and y 
20140925 

seyilogo pose la question : solve y=2x  3 and (4x  2y) / x + y = 1 simultaneously Harley Weston lui répond. 





Two equations in two variables 
20140918 

Susan pose la question : (28x + 36y)  [20000  .75(28x + 36y) + 60000] = 5000
x + y = 10000
solving two equations involving variables Penny Nom lui répond. 





A six team track schedule 
20140915 

Paul pose la question : I need to make a six (6) team track schedule. It needs to be five (5) triangular (3 team) meets with each team playing each team twice Victoria West lui répond. 





Cutting a round cake so that it doesn't dry out 
20140826 

James pose la question : I'm wondering if there's a simple way to calculate the area between two parallel chords of a circle equidistant from its diameter, or if I have the area, to find the distance between the two chords.
Here's my "problem". You may have heard of the way of cutting a round cake so that it doesn't dry out  make two parallel cuts (chords) the length of the cake, take the middle piece, then push the two pieces together.
So I know the area of a 12" cake, and I want say, exactly an eighth of the cake. How wide do I cut the centre piece?
Now to get even more difficult, the next day I want another eighth from the centre. How wide do I cut the next pieces, and so on...?
Thanks,
James Harley Weston lui répond. 





Revisiting 8 golfers in two foursomes 
20140819 

steve pose la question :
I noticed you had an answer on how can you put 8 golfers in even foursomes over 7 games so that everyone plays with everyone equally. However the formula showed the following sequence that was used but did not go past the second day. Can you change the 0s and 1s into the numbers 1 to 8 instead. Here is what you have written:
Day 0 : (0, 0, 0, 0, 1, 1, 1, 1)
Day 1 : (0, 0, 1, 1, 0, 0, 1, 1)
Day 2 : (0, 1, 0, 1, 0, 1, 0, 1)
Day 3 : (0, 1, 1, 0, 1, 0, 0, 1)
Day 4 : (0, 0, 1, 1, 1, 1, 0, 0)
Day 5 : (0, 1, 0, 1, 1, 0, 1, 0)
Day 6 : (0, 1, 1, 0, 0, 1, 1, 0)
Thank you so much for your anticipated help.
Steve Harley Weston lui répond. 





A barge of triangular cross section 
20140818 

tushar pose la question : a barge of triangular cross section is 20m long 12 m wide and 6m deep.its floats in SW at a draft if 4m find its displacement Penny Nom lui répond. 





How do you convert square mm to square cm? 
20140813 

David pose la question : How do you convert square mm to square cm? Tyler Wood lui répond. 





4821x14y is an 8digit number divisible by 72 
20140806 

RAYA pose la question : if 4821x14y is an 8digit number divisible by 72. How many values can x and y take? Penny Nom lui répond. 





The dimensions of a rectangle 
20140803 

Jamaica pose la question : if the perimeter of a rectangle is 30m and its area is 56 m2.find its length and width? Penny Nom lui répond. 





The sum of the first 50 terms of an arithmetic progression 
20140726 

Joshua pose la question : Hello ...my is Joshua...I'm a grade 11 student...I got a question
Calculate the sum of the first 50 terms of an arithmetic progression: 112:98:84 Penny Nom lui répond. 





An octagon around a tree 
20140716 

floyd pose la question : I want to build an octagon 4 feet from base of tree from 4x4's. What length do I cut my pieces Penny Nom lui répond. 





Solve sin3x = cos2x 
20140714 

Emanuel pose la question : If sin3x=cos2x, find the value of x when x<0<90' Penny Nom lui répond. 





A 5 sided lot 
20140710 

mia pose la question : have the feet numbers of three sides, but the forth side is in a "V" so it has two figures.
Question: can i add the two figures of the "v" together to get one figure, so then I would have the figures for all four sides. Harley Weston lui répond. 





67 cubic yards in cubic metres 
20140709 

gavin pose la question : Convert 67 cu yards into cu metres Penny Nom lui répond. 





The method of elimination 
20140705 

leo pose la question : please explain how can i solve this problem
3x6y=38
6x9y=44
using elimination and simultaneous method thank you :) Penny Nom lui répond. 





A six digit number 
20140630 

anupam pose la question : hi,
my daughter asking a solution for the below question, kindly help.
Write the smallest 6 digit number wit digits ( 2,4,3,0,5,7).
plz this is an urgent requirement.
regards,
anupam Penny Nom lui répond. 





Simultaneous equations 
20140620 

rana pose la question : solve the simultaneous equations
a)3x=7y
12y=5x1 Penny Nom lui répond. 





Two regression lines 
20140614 

catherine pose la question : Given a set of data values ,we can get two regression lines .Explain. Robert Dawson and Penny Nom lui répond. 





A small solid silver pyramid 
20140613 

Jenesis pose la question : For Awards Night at Baddeck High School, the math club is designing small solid silver pyramids.The base of the pyramids will be a 2 in by 2 in square. The pyramids should not weigh more than 2.5 pounds. One cubic foot of silver weighs 655 pounds. What is the maximum height of the pyramids? Penny Nom lui répond. 





The weight of salt in a basket 
20140517 

Sumit pose la question : I want to determine how many kg of salt or XYZ thing can be filled in a basket
Length = 4.5"
Breadth = 5"
Height = 6"
Even its formulae
is kg quantity can be different for semi solid thing Penny Nom lui répond. 





The length of a shadow 
20140509 

vijay pose la question : A girl of height 80 cm is running away from the base of a lamppost at a speed of 2 m/s. If the lamp is 4 m above the ground, find the length of her shadow after 5 seconds. Penny Nom lui répond. 





A cone of vision 
20140429 

David pose la question : It is known that a fish in water looking up has a 97 degree "cone" of vision that sees "through" the surface of the water. If a fish lies 4 inches below the surface, the cone forms a window (circle) smaller than if a fish lies 8 inches below the surface. What is the ratio of inches of depth to the radius of the circle on the surface that is its visual window? Penny Nom lui répond. 





A triangular chicken pen 
20140427 

Cierra pose la question : Margaret has two lengths of fence, 20 meters and 24 meters, for two sides of a triangular chicken pen. The third side will be on the north side of the barn. One fence length makes a 75° angle with the barn. How many different pens can she build if one fence is attached at the corner of the barn? What are all the possible lengths for the barn side of the pen?
Not sure what they are asking here... please show step by step what to do! Thank you so much! Penny Nom lui répond. 





The derivative of sin(x) 
20140426 

Lucky pose la question : f(x)=Sin(x), by first principle its f'(x)...show me how to solve such problem. Penny Nom lui répond. 





Simultaneous equations with fractions 
20140419 

Maryam pose la question : I looked at your example of simultaneous equations with fractions and applied it to my question from an educate exam papers but I couldn't get it to work. The question is:
x/8  y = 5/2
3x + y/3 = 13 Penny Nom lui répond. 





A slab of wet clay 
20140412 

Karen pose la question : How many square feet ( at 1/4 inch thickness) are in 100 lbs. of wet clay? Penny Nom lui répond. 





Two cones 
20140409 

c.j pose la question : what is the length of the radius of the LARGER cone(the LARGER cone has a slant height of 15) when the SMALLER cone has a radius of 8 and a slant height of 12ft ,please help. Penny Nom lui répond. 





The sides of a triangle 
20140406 

Michael pose la question : I am supposed to sove for the length of side "b" of an irregular triangle. I am given the following:
Side a: 65'
Side b: Find this length
Side c: 50'
Angle A: unknown
Angle B: unknown
Angle C: 52 degrees
I am supposed to use the law of cosines to solve for side "b" and my teacher
says there is no mistake in the "givens" for the problem. I do not see how
this can be done using the law of cosines and i have not figured out how to sove for
angle B to use the law of cosines. Penny Nom lui répond. 





A 4 digit number 
20140404 

LIM pose la question : "A" is a 4 digit number formed by all the numbers from 1 to 4. When "A" is divided by 9, the remainder is the biggest possible value. What is the biggest value of A? Chris Fisher lui répond. 





Shadows of a father and son 
20140402 

esada pose la question : the father and son cast a shadow of 11 feet and 8 feet,respectively if the son is 4'8'' in height,how tall is the father? Penny Nom lui répond. 





Reducing the size of a poster by a scale factor of 1/3 
20140401 

deeshon pose la question : eric is making a smaller copy of a poster that measures 20.4 cm wide by 34.2 cm long.he reduces the original by a scale factor of 1/3.what are the dimensions of the copy Penny Nom lui répond. 





An arithmetic progression 
20140331 

Japheth pose la question : The 3rd term of an A.P is 10 more than the first term while the fifth term is 15 more than the second term. Find the first term? Penny Nom lui répond. 





A formula for determining concrete volume in cu. yd. 
20140319 

Steven pose la question : I know a couple of formulas for determining concrete volume in cu.yd. the one I use most frequently is length in feet x width in feet x thickness in inch. Divided by 324. It works every time. Where does the number 324 come from. Penny Nom lui répond. 





The area of a 5 sided lot 
20140315 

Michael pose la question : Question from michael:
This lot is in feet. 59x154x109x188x137 per the plot plan Harley Weston lui répond. 





A parabolic suspension bridge 
20140311 

jeffrey pose la question : the towers of a parabolic suspension bridges 200 meter long are 40 meter high and the lowest point of the cable is 10 meter above the roadway.Find the vertical distance from the roadway to the cable at 50 meter from the center. Penny Nom lui répond. 





Simple interest 
20140308 

lynn pose la question : I need to find what the interest will be for: 5000.00 @ 16.5%
annual rate, and the same for 10.8 % for 5000.00 annual rate all one question
thank you for your aid Penny Nom lui répond. 





The angle of depression 
20140308 

Ranger_minor pose la question : A woman of height 1.4 metres standing
on the top of a building 34.6 metres high
views a tree some distance away.
she observes that the angle of depression of the bottom of the tree
is 35 degrees and the angle of depression of the top of the tree
is 29 degrees.
assume that the building and the tree are on level ground :
1). calculate the distance of the woman
from the top of the tree measured along her line of sight. Penny Nom lui répond. 





Simultaneous fractional equations 
20140215 

benjamin pose la question : hi math central. benjamin here. during class, i had problem with this topic. normally i wont have problems with math but this topic i just too hard for me. please help i am having exam and test next week on this topic
here is the question:
using substitution method, solve the simultaneous equation.
(x+1)/(y+2)=0.5
(x2)/(y1)=1/3 Penny Nom lui répond. 





Converting cost per cubic yard to cost per ton 
20140205 

Mayra pose la question : If 18 cubic yards= 25 tons and it's $28.00 per yard how much is it a ton. I need help please a refresher on my algebra. Thank you Penny Nom lui répond. 





Two nonlinear equations 
20140126 

Naryn pose la question : (1÷x) + (1÷y) = (7÷12)
xy = 12 Penny Nom lui répond. 





When would one flip the inequality sign? 
20140109 

Natasha pose la question : Would one flip the inequality symbol in this equation: (explain why)
(9a)/(9) > 81
And please explain in what circumstances one would flip the inequality sign
THANKS! Penny Nom lui répond. 





An arithmetic sequence 
20140106 

paris pose la question : find the twentyfifth term of an arithmetic sequence whose first term is 12 and whose common difference is 6 Penny Nom lui répond. 





25% profit 
20140102 

Finn pose la question : Hello,
The question is all about buyandsell business.
Problem:
Pencil  $6 for whole sale price
$8 if I sell the item
How do I get the 25% profit? (you can change the whole sale price and the retail price[if i sell the item])
if I buy the pencil at 24 pieces and sell it at 24 pieces. Penny Nom lui répond. 





0.35 as a fraction 
20131128 

Laura pose la question : How do you write 0.35 as a fraction or mixed number?
Laura Penny Nom lui répond. 





Substitution type simultaneous equations 
20131103 

Kayla pose la question : I am having problems with substitution type simultaneous equations, when the variable you are substituting is a algebraic one:
y=x^23x+4 and 3x2y=1
I have rearranged 3x2y=1 to get x=(1+2y)/3 but when I substitute this x value into the other equation, I get the wrong answers!
Would appreciate any help! Thank you. Penny Nom lui répond. 





Proportional rates 
20131010 

Varsha pose la question : A province's Ministry of Social services has found that both the number of people needing social assistance and the province's total expenditures on social assistance are proportional to the rate of unemployment. Last August when the provincial unemployment rate was 8.4 %, the province provided assistance to 89,300 individuals at a total cost of 4107.4 million. The forecast unemployment rate for next August is 7.9%. How many people can the province expect to need social assistance next August? What amount should the province budget for social assistance in August? Penny Nom lui répond. 





How many cubic centimetres are there is a cubic meter? 
20131010 

Larry pose la question : Change 1meter(to 3rd power) to centimetre(to 3rd power).
This is a metric conversion problem Penny Nom lui répond. 





An Arithmetic Progression 
20131008 

collins pose la question : In an A.P. the difference between the 8th and 4th term is 20 and the 8th is one and half times the 4th term... what is the common difference and the first term Penny Nom lui répond. 





A triangle problem 
20131002 

raneem pose la question : ABC is a triangle in which : BC=20cm. M(<B) =29 and m(<C)=73 . D is the midpoint of BC
Find the length Of AB and AD approximated to 2 decimal places Penny Nom lui répond. 





A schedule for 2, 7 team divisions 
20130924 

Sampson pose la question : I'm looking to set up a weekly schedule within a 22 week segment of 2 7 team divisions where every team plays every other team in their divison 3 times and have 4 cross over games with 4 of the other 7 teams in the other division. I've yet to figure this out.
Thanks for your time. Victoria West lui répond. 





Miles per minute to miles per hour 
20130908 

Adam pose la question : Convert 250 miles per min to miles per hour Penny Nom lui répond. 





How we convert cm to mm? 
20130908 

Génesis pose la question : How we convert cm to mm? Penny Nom lui répond. 





The sum of all whole numbers from 1 to X 
20130906 

Tim pose la question : How do I develop a rule for the sum of all whole numbers from 1 to X when I have no idea how to do this Penny Nom lui répond. 





A sequence or a series? 
20130905 

Rahul pose la question : Whether the following sequence is increasing or decreasing? I even do not kow whether to call it a sequence or not. an = (1/(1+n))+(1/(2+n))+....+(1/(n+n)).
I am confused. It looks like a series to me. Please help.
Regards,
Rahul Robert Dawson lui répond. 





Tesseract 
20130822 

Dan pose la question : I am not a mathematician. This seems to me an intuitively simple enough problem that I very much need an answer to from someone who's mathematics are better than mine. Please help.
The question is: for a tesseract of side length = 1
what is the distance of the center of each cube from the center of the tesseract ?
I think I have calculated the distance of each vertex from the center, and of the center of each edge from the center, but the question above baffles me.
(anyone not having a clue what I am talking about can brush up here http://en.wikipedia.org/wiki/Tesseract )
Thanks in advance  Dan V Robert Dawson lui répond. 





Similar rectangles 
20130817 

Mattie pose la question : The dimensions of a rectangularshaped picture frame are 14 inches long and four inches wide. Which dimensions below represent another frame that i geometrically similar>
a. l=49 in. and w=14in.
b. l=7in and w=3in
c. l=21in and w=8in
d. l=24in and w=14in
thanks Penny Nom lui répond. 





Using trig to find the height of a hill 
20130814 

Anna pose la question : From the top of a hill, the angles of depression of two successive milestones on a level road, which leads straight away from the hill, are 5degrees and 15degrees respectively. Fine the height of the hill.
Suggestion: BE is drawn perpendicular to AD. Find BE, then BD, finally CD.
Thanks :) Penny Nom lui répond. 





A triangle construction 
20130727 

Nazrul pose la question : Two angles and the difference of the lengths of their opposite sides of a
triangle are given. How can I draw the triangle.
Please help me. Chris Fisher lui répond. 





What is the smallest number? (i.e. the closest number to zero) 
20130722 

Charlie pose la question : What is the smallest number? (i.e. the closest number to zero) Harley Weston lui répond. 





Simultaneous equations 
20130710 

Warren pose la question : solve this simultaneous equation: xy=4
2x+3y=14 Penny Nom lui répond. 





An arithmetic progression 
20130706 

ashok pose la question : the 4th and 10th term a.p respectively 7 and 19 find its 15th term..... Penny Nom lui répond. 





A 3 acre plot 
20130617 

Chad pose la question : I have 3 acres 100ft at the top and bottom what is the length of each side to make up the 3 acres Penny Nom lui répond. 





{(1+x)^1/31/3X(1+x)^2/3}/(1+x)^2/3 
20130617 

STEPHEN pose la question : {(1+x)^1/31/3X(1+x)^2/3}/(1+x)^2/3 Penny Nom lui répond. 





An isosceles tiangle 
20130616 

Izzy pose la question : what's the height of an isosceles triangle which has a base of 50 m, and both of the other sides are 25 m? Penny Nom lui répond. 





Simson line 
20130523 

Nazrul pose la question : From any point p lying on the circumcircle of the triangle perpendiculars
PD , PE are drawn on BC,CA respectively. The line segment ED intersects at
the point 0 ; prove that PO ⊥ AB ( PO is perpendicular to AB ). Chris Fisher lui répond. 





A 2digit number 
20130513 

A teacher pose la question : Find a “2digit number” where the sum of the 1st digit (on the Left)
and the square of the 2nd digit equal the same number. Lorraine Dame, Harley Weston lui répond. 





siin (A) and sin (A/2) 
20130509 

shanaia pose la question : given that sin A=4/5 and A is obtuse.find sin (A/2) Penny Nom lui répond. 





A silver figurine 
20130503 

Renee pose la question : I have a silver figurine, the density of silver is 10.5g/cm3. if the figurine weighed 149 g. to determine the volume, he dropped it into a cylindrical glas of water. the diameter of the glass is 6 cm and the figurine was pure silver, by how much should the water level in the glass rise? Penny Nom lui répond. 





How can we draw the equation "x+y=1" in 3d? 
20130503 

shimaa pose la question : how can we draw the equation "x+y=1" in 3d Robert Dawson lui répond. 





How do i reverse this formula? 
20130420 

MK pose la question : I have 22,000,000 worth of gold and wants to want to resell the gold back with a profit.
Each transaction of gold will have a transaction fee of 15%, so if i resell the gold back at 22,000,000, I will only get back 18,700,000 after 15% transaction cut.
The current formula is X15%X = Y where X = 22,000,000 and Y = 18,700,000
Will u be able to come up with a new formula if we don't know the value of X but we know the value of Y
Something like this X15%X = 22,000,000.
How do i reverse this formula to find the value of X
Thanks Penny Nom lui répond. 





4 linear equations with 3 unknowns 
20130412 

Marian pose la question : how to solve for 3 unknowns in 4 simultaneous equations Penny Nom lui répond. 





The distance between 2 lines in 4D 
20130401 

samane pose la question : how can i measure the distance between 2 lines in 4D?? Chris Fisher lui répond. 





We can't write sinx and cosx as a finite polynomial. 
20130331 

rimoshika pose la question : prove that we can't write sinx and cosx as a finite polynomial. Walter Whiteley lui répond. 





Simultaneous equations with fractions 
20130331 

Terence pose la question : 5/x6/y=1
17/x+30/y=16
I been spending whole day to solve this question. Would be very grateful if you can help I try
The denominator value is a equations term which make is simultaneous equations so hard. Penny Nom lui répond. 





The dimensions of a rectangle 
20130319 

stephanie pose la question : the length of a rectangle is 5m more than twice its width, and the area of the rectangle is 88m^2 find the demensions of the rectangle Penny Nom lui répond. 





Sixdigit passwords 
20130319 

Judy pose la question : Hello:
Can you please explain why the answer to the following question is 10^6?
What is the number of possible sixdigit passwords when using the digits 0 through 9, with repetition allowed.
Thank you. Penny Nom lui répond. 





An algebraic exercise 
20130318 

autumn pose la question : given: f(x)=x/(x^2+2) determine: [f(xh)f(x)]/h Penny Nom lui répond. 





A messy arithmetic expression 
20130224 

niiaryee pose la question : (((((5^2*4^3)1/5+9^3/3)+(25+(4*5)/15)^210)/10/2)3))))) Penny Nom lui répond. 





Fractions over fractions 
20130222 

Kenssa pose la question : Question from Kenssa, a parent:
Simplify: 3(7/x)(6/x^2) / (3/x^2)+(5/x)2 Harley Weston lui répond. 





The continuity of f(x,y)=ln(x^2+y^2) 
20130217 

anu pose la question : the question says we have to find the points in the plane where the function is continuous:
f(x,y)=ln(x^2+y^2) . here we aren't given a particular point (x,y) where we have to check a function's
continuity.
what is to be done if we have to check continuity over the whole domain of the function?
please help . Harley Weston lui répond. 





A word problem involving toys 
20130214 

sandy pose la question : Each boy gets 5 toys.Each girl gets 3 toys.There are 150 pupils.
The boys had 74 more toys than girls.
How many boys?
How many girls? Penny Nom lui répond. 





Simultaneous equations 
20130210 

Michael pose la question : 2P + 1/3V =8
3P  2/V=5 Penny Nom lui répond. 





An arithmetic progression 
20130206 

loberto pose la question : the 3rd term of an a.p is 10more than the 1st term,while the 5th term is 15more than the 2nd term,find the sum of the 8th and 15th terms of the a.p if the 7th term is 7times the 1st term Penny Nom lui répond. 





A relation on a collection of sets 
20130204 

raji pose la question : suppose R be a non empty relation on a collection of sets defined by ARB if and only if A intersection B is nullset.then.....the correct answer is R is symmetric and not transitive...my doubt is how it is symmetric Penny Nom lui répond. 





The fourth side of an irregular polygon 
20130201 

Emran pose la question : I have a irregular polygon. I know 3 of the 4 sides, and 2 of the angles. AB is 285, BC is 149, and CD is 310. Angle B is 135 degrees. and Angle C is 45 degrees. Is there a formula to solve for the final side? Thanks. Penny Nom lui répond. 





The weight of a pipe full of water 
20130116 

joe pose la question : how do you figure out the weight of a pipe full of water Harley Weston lui répond. 





A balance puzzle 
20130114 

Emily pose la question : I'm stuck on this problem and feel that it can't work! The problem is: there is a door with a balance scale on it. In order to open the door, you have to use the 5 weights to balance the scale. On the left side you have 2 boxes to place the weights and on the right side you have 3. You're 5 weights are as follows: 1lbs, 2lbs, 3lbs, 4lbs, 5lbs. How do you place the weights so that the scale is balanced? Penny Nom lui répond. 





The side lengths of a triangle 
20130107 

Katie pose la question : How do I find the side lengths of a triangle knowing the base and its height?
Thank you, Penny Nom lui répond. 





A triangular island 
20121229 

Udit pose la question : A long time ago Mr Gibson found an island shaped as a triangle with three straight shores of length 3 km,4 km and 5 km. He declared an 'exclusion zone' around his island and forbade anyone to come within 1 km of his shore. What was the area of his exclusion zone? Penny Nom lui répond. 





A 12 acre parcel of land 
20121228 

John pose la question : What are the dimensions of a 12acre parcel if it is 3 square acres deep and 4 square acres wide? Penny Nom lui répond. 





Two polynomials are divisible by x  2 
20121226 

Tehmas pose la question : Determine the values of m and n so that the polynomials 2x^3+mx^2+nx3 and x^33mx^2+2nx+4 are both divisible by x2. Penny Nom lui répond. 





The last 4 digits of a cell phone number 
20121222 

Jacob pose la question : If the last 4 digits of a cell phone number, XXXXXXABCD, are restricted where: A cannot be 0 or 1 and B cannot be 0 / how many possible 4 digit combinations are left? Penny Nom lui répond. 





A project on reclaiming water 
20121211 

shannon pose la question : I'm doing a report to reclaim water off of our campus facility to store in a cistern to use to flush toilets.
In Southeast Wisconsin and average of 82 inches of rain and snow fall annually.
I want to collect that off of the roof of our school building.
The roof is 37128 square feet.
how many gallons annually could I collect? Penny Nom lui répond. 





The angles of elevation and depression 
20121203 

Chelsey pose la question : a person on a balcony of one building looks towards a second building. if the angle of elevation to the top of the second building is 25 degrees, the angle of depression to the bottom of the second building is 17 degrees, and the balcony of the first building is 22 feet above the ground, what is the height of the second building? Penny Nom lui répond. 





Transposition error 
20121203 

Carol pose la question : What is the correct term for when a child writes 61 instead of 16, or 83 for 38when they switch the place values of a number? Chris Fisher lui répond. 





A function problem 
20121118 

nahla pose la question : f: IN > IN
n > f(n)
for every n that belongs the IN : fof(x) = 4n  3
and for every n that belongs to IN f(2^n) = 2^(n+1) 1
Calculate f(993) Penny Nom lui répond. 





The square of any odd number, decreased by 1, is divisible by 8 
20121116 

bailey pose la question : Prove that the square of any odd number, decreased by 1, is divisible by 8 Penny Nom lui répond. 





A mathematical expression with the answer 7 
20121110 

emily pose la question : hey um i need to find and problem that fallows bedmas that has one division one multiplication and one sub and one add and one brackets and one exponents that has the answer of number 7 Penny Nom lui répond. 





Forming an algebraic expression 
20121027 

ashley pose la question : A sidewalk has a constant width W and comprises several short sections having lengths
12, 14,and 10 feet. How do I find the simplified expression that gives the number of square feet of sidewalk? Penny Nom lui répond. 





Some 6 digit numbers 
20121023 

Mason pose la question : How many different 6 digit numbers can you make using the digits 1 ,2 5, 6, 7, and 9? How many of these sixdigit numbers are divisible by 6? Penny Nom lui répond. 





A 2 acre plot 
20121022 

bob pose la question : If a plot of land on the south side is 290.16 feet wide, how many feet on the west and east side to the north to make a 2 acre plot?
Thank You Bob Penny Nom lui répond. 





Converting a fraction to a decimal 
20121020 

A Teacher pose la question : My students want an easy way to convert a fraction to a decimal, can I get one from you? Penny Nom lui répond. 





A proof by contraposition 
20121019 

Rahul pose la question : I am not able to understand the following,
To prove that if for all e>0, x0, then x>=e. I understand the approach very well but I do not understand why if x=e then x>=e. If it is so then why not x=
Thanks in advance!'
Rahul. Penny Nom lui répond. 





Composition of functions and one to one 
20121017 

Ariana pose la question : If f o g are one to one function,does it follow that g is one to one? Give reasons for your answers Penny Nom lui répond. 





A word problem involving a fraction 
20121012 

Derrick pose la question : If the numerator and denominator of a fraction are both decreased by 1 the fraction becomes 2/3. If the numerator and denominator are both increased by 1 the fraction will be 3/4. Find the original fraction. How to do? Penny Nom lui répond. 





Find an algebraic expression 
20121003 

Karen pose la question :
Question from Karen, a parent:
Find an algebraic expression relating the input and output.
input 
output 


3 
1 
9 
3 
15 
5 
21 
7 
27 
9 
Penny Nom lui répond. 





A problem involving simple interest 
20120927 

Tash pose la question : The amount of money in a single year of an investment after P dollars were initially invested is A = P + Prt, where r is the rate of simple interest. What expression describes P? How much money was initially invested if the account has $1000 one year after the initial investment and the interest rate was 5%? Penny Nom lui répond. 





Changing the sign of an inequality 
20120919 

Bryauna pose la question : Why do you change the signs in inequalities?! Penny Nom lui répond. 





The dimensions of a rectangle 
20120912 

Becky pose la question : A rectangle has an area of 48 square inches and perimeter of 32 inches. Find the dimensions of the rectangle. Penny Nom lui répond. 





Six digit numbers 
20120911 

Fiona pose la question : using the numerals 0, 2, 3, 5, 7, 9, make as many sixdigit numbers as you can. Rearrange them into ascending order Robert Dawson lui répond. 





Minutes and seconds 
20120829 

Casey pose la question : I have to write a variable equation. The questions says there are 60 seconds. but we need to write and equation to solve for minutes. Is it 1/60 or 1/s Robert Dawson lui répond. 





Vector division 
20120828 

Nazrul pose la question : If A and B be two vectors where B = 3 A The What is B/A ?
Please help me. Robert Dawson lui répond. 





An arithmetic progression 
20120822 

A student pose la question : the 3rd term of an A.PPP is 10 more than the first term while the 5th term is 15 more than the second.find the sum of the 8th and 15th terms if the 7th term is 7 times the first term. Penny Nom lui répond. 





0.687 acres in square feet. 
20120718 

Roy pose la question : The land parcel I am looking at says Acreage .687 how do I determine square feet? Robert Dawson lui répond. 





A sand box with 14 sides 
20120710 

Tom pose la question : Want to build a sand box for a pool that is fourteen foot round wanted to make it in fourteen pieces of wood what angle would each piece be and how long would each piece be Harley Weston lui répond. 





Six people divided into three groups of two 
20120709 

Fatima pose la question : Six people call them A,B,C,D,E,F are randomly divided into three groups of two,find the probability of the below event(do not impose unwanted ordering among groups)
E andF are in the same group
I solved it but I have a doubt that it is wrong .
My answer is 576
Please help to solve this problem. Lorraine Dame and Penny Nom lui répond. 





An octagonal sandbox around a pool 
20120612 

Linda pose la question : My pool is 15 feet across and it is round.
How do I measure to cut wood to build a sandbox around it? was thinking it will look like an octagon.
Thanks Harley Weston lui répond. 





The position of an aircraft relative to the airport 
20120608 

Dennis pose la question : "Air traffic controllers usually describe the position of an aircraft relative to the airport by altitude, horizontal distance, and bearing. Suppose an aircraft is at altitude 500m, distance 15km, and bearing 35 degrees east of north. What are the x,y, and z components (in meters) of the position vector. The xaxis is east, the yaxis is north and the zaxis is vertical. Penny Nom lui répond. 





Long division 
20120607 

Emily pose la question : Simplify the expression using long division (9x^241x6)/(x4) Penny Nom lui répond. 





Division in base eleven 
20120527 

Zoe pose la question : How do you divide numbers that are in base 11?
For example;
9A7A6A divided by A Penny Nom lui répond. 





cos(theta/30) = 1 
20120514 

Hope pose la question : cos (theta / 30 = 1
I am very confused as to how to solve it. Can you help? Penny Nom lui répond. 





The dimensions of a rectangle 
20120430 

Nikki pose la question : Name the dimensions of a rectangle that has the same area as this triangle?
I found the area of the triangle, which is 30. What do I have to do in order to complete this math problem? Penny Nom lui répond. 





Third side of a irregular triangle. 
20120427 

Darya. pose la question : How to find third side of irregular triangle if c = 17m, b = 28m and area S = 210m^2. Penny Nom lui répond. 





How to find the base length of a isosceles triangle if only the sides are given? 
20120425 

aqilah pose la question : how to find the base length of a isosceles triangle if only the sides are given? Chris Fisher lui répond. 





A rectangular prism 
20120405 

Tori pose la question : How do you find the base height if the base width is 10ft. The height is 7ft. And the volume is105ft. Penny Nom lui répond. 





A uniform probability density function 
20120326 

Noeline 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. 





Forming a triangle from 3 line segments 
20120315 

rustom pose la question : A point X is selected at random from a line segment AB with midpoint 0. Find the probability that the line segments AX, XB, and A0 can form a triangle. Penny Nom lui répond. 





The dimensions of a rectangle 
20120313 

irvyn pose la question : if you are only given the area and the perimeter how do you find the dimension? Penny Nom lui répond. 





The dimensions of a conical tent 
20120304 

yash pose la question : a conical tent is to accommodate 11 people.Each person must have 4m square of space on the ground and 20m cube at air to breathe.Find the height and radius of the conical tent.26202 Penny Nom lui répond. 





Integral 1/(25x^2)^3/2 
20120222 

John pose la question : Integral 1/(25x^2)^3/2 Harley Weston lui répond. 





The 10000th day of her life 
20120221 

derrick pose la question : Ella was born early in the morning on a Friday.She got married on the 10000th day of her life. What day of the week was it? Penny Nom lui répond. 





Simplify the expression 
20120212 

Christy pose la question : Hi guys, ok so I'm having problems with solving this equation since it's been so long I've done precal.
I have to find critical points so I have to find the derivative first. This is what I've done so far
s(t)= (t6)^4 * (t+1)^2
t'= 4(t6)^3*(1)*(t+1)^2+ 2(t+1)(1)*(t6)^4
so this is where I got stuck, which is the algebra part. How can I simplify this to get the answer to figure out the critical points. Penny Nom lui répond. 





Litres in a box 
20120209 

vicky pose la question : how much litre water can be filled in a box of 12 inches *24 inches *12inches Penny Nom lui répond. 





A tree growth modelled by a geometric series 
20120208 

Steph pose la question : Hi I am really struggling with this question please help !!!!
a pohutukawa tree is 86 centimetres when it is planted. in the first year after it is planted , the tree grows 42 centimetres in height.Each year the tree grows in height by 95% of the growth of the previous year.
assume that the growth in height of the pohutukawa tree can be modelled by a geometric sequence.
A)find the height of the tree 5 years after it is planted and figure out the maximum height the pohutukawa tree is expected to reach in centimetres Penny Nom lui répond. 





The curvature of the earth 
20120208 

sean pose la question : Question from sean, a student:
Two people 1.8 metres tall walk directly away from each other until they can no longer see each other (due to the curvature of the earth, which has a radius of about 6378 km).
A) Find a function relating the height of two identical objects with the distance between them using the scenario above as an example.
B) Sketch this function (you may use Graphmatica if you wish). Over what domain and range does the function exist?
C) Describe this relation in practical terms. Harley Weston lui répond. 





The dimensions of a rectangle 
20120131 

Dazz pose la question : Hi I was wondering how to find the length of a rectangle if you know the area is 484 square inches And the length is 10 square inches or 22 square inches?
Thanks~Dazz Penny Nom lui répond. 





1 + 3 + 3^2 ...+3^(n1) = 3^n  1/2 
20120127 

Vicki pose la question : I am trying to find out how to do show how this proof was worked.
Here is the end result 1 + 3 + 3^2 ...+3^(n1) = 3^n  1/2
This equation was used to find the number of white triangles in the Sierpinski Triangle Walter Whiteley lui répond. 





Tangent of theta 
20120117 

stahl pose la question : explain what the 'tangent of theta' means. Draw and label a diagram to help with your explanation. Harley Weston lui répond. 





One acre of dirt 6 inches deep 
20120111 

Cameron pose la question : Ok what im wanting to know is how many pounds of dirt are in 80
acres of land that is 6 inches deep? My friend and I are stumped on this question Penny Nom lui répond. 





The dimensions of a rectangle 
20120106 

joseph pose la question : The perimeter of a rectangle is 72 inches. The length of the rectangle
is three more than 2 times the width of the rectangle. What is the
length of the rectangle? Write and solve an equation to determine the
dimension of the rectangle. Penny Nom lui répond. 





Limits and composition 
20111230 

Rahul pose la question : I want to know about limit proofs of composite functions. Like limit of log of a function equals log of limit of the function Penny Nom lui répond. 





Three sides of a triangle 
20111224 

saba pose la question : the three sides of a triangular lot have lengths 10,11and 13cm,respectively.
find the measure of its largest angle and the area of the lot? Penny Nom lui répond. 





The weight of 36 inch steel pipe 
20111222 

Keith pose la question : What is the weight of 36 inch steel pipe 3/4 wall per foot in lbs. Penny Nom lui répond. 





i+i^2+i^3+i^4...+i^102 
20111213 

megan pose la question : how do you solve i+i^2+i^3+i^4...+i^102 Robert Dawson lui répond. 





Simple interest 
20111211 

sandeep pose la question : Use the formula I = Prt to solve.
Damon deposits $500 into a savings account that pays simple interest
at a rate of 0.65% per year. How long will it take Damon to earn $130
in interest? Penny Nom lui répond. 





Squares and triangles 
20111206 

Liaqath pose la question : You have squares and triangles.
Altogether there are 33 sides.
How many squares do you have?
How many triangles do you have? Penny Nom lui répond. 





A suspension bridge 
20111130 

jennifer pose la question : suspension bridges like the golden gate bridge, are used to span large distances.
when the main curved cables are attached to the deck by vertical cables they will end
up in the shape of parabola. assume that we need to build a bridge that spans
2,400 feet. the two towers 165feet tall each where placed at 400feet from either
side. the lowest point of the center of the bridge at 10feet. vertical suspension cables
where placed at 25foot interval. how many feet of cable are needed to connect
the deck to the main cables between the two towers? show all working. Penny Nom lui répond. 





The 3rd term of an A.P is 10 more than the first term 
20111129 

Olaniyan pose la question : the 3rd term of an A.P is 10 more than the first term while the fifth term is 15 more than the second term. Find the sum of the 8th and 15th terms of the A.P if the if the 7th term is 7 times the first term. Penny Nom lui répond. 





Converting from base 4 to base 10 
20111129 

anjg pose la question : How to convert base 4 number 2^11 to base 10 number? Penny Nom lui répond. 





An arithmetic expression 
20111128 

Muhmmad pose la question : 2/5*3/71/6*3/2+1/14*2/5 Penny Nom lui répond. 





The LCM of 6,15 and x is 90 
20111030 

Richie pose la question : Hi there,
There are 2 parts to the question.
#1. Factorise 90. This is easy, 90=2x3x3x5
#2
LCM of 6,15 and x is 90. What are possible values of x if x is odd?
From #1, since 90=6x15, how can this be used to work out possible values of x?
Thanks in advance,
Richie Penny Nom lui répond. 





A mythical soccer ball 
20111027 

Joel pose la question : We've been working on this problem diligently and can't seem to come up with the answer book's answer. We think it may be wrong, yet want to check it with an expert. Here goes.
The school's new soccer balls are covered with 64 regular hexagonal panels. Each hexagon measures 2 inches between opposite corners and 1.5 inches between opposite sides. What is the total surface area of the soccer ball? Robert Dawson and Lorraine Dame lui répond. 





1 divided by 0 and infinity 
20111024 

ritika pose la question : we say that one divided by zero gives us infinity, then why zero multiplied by infinity does not gives us one????????????? Robert Dawson lui répond. 





A 6% commission 
20111015 

Tamara pose la question : if you earned a gross wage of $810, which includes a salary of $90 and a 6% commission how much is the net sales? Penny Nom lui répond. 





The sides of a regular octagon of area 800 sq. ft. 
20110921 

Susan pose la question : Help please. I am building an octagon tree house to live in. I would
like the total square footage to equal 800 to 1,000 sq ft. How long
should each side of the octagon be.
tx, susan Penny Nom lui répond. 





A four digit number 
20110916 

gina pose la question : i am having a hard time figuring this out.. i believe the answer is 3105 but the 0 is throwing me off... i am a 4 digit number between 3100 and 3200, none of my digits are even, the sum of my digits is 9, the largest digit is in the ones place, what number am i ?? Penny Nom lui répond. 





Composition of functions 
20110905 

Jenna pose la question : Let f(x)=x^21 and g(x)=12x. Find the indicated values.
1. f(g(1)) and g(f(1))
Thanks,
Jenna Penny Nom lui répond. 





The dimension of the box in centimetres 
20110827 

Eliza pose la question : Find the dimension of the box in centimetres. Then find its volume in cubic centimeters.
The box is 0.7m (l) 0.4 (h) 0.2 (w) Penny Nom lui répond. 





58 choose 4 
20110826 

Jean pose la question : Using only the numbers 159, how many times would the
number 23 appear in combinations of 5 numbers?
... Can a list be provided as well?
Thank you very much,
Jean Penny Nom lui répond. 





A trapezoid 
20110802 

Nazrul pose la question : How can I draw a trapezoid whose parallel sides and other two sides are given. Chris Fisher lui répond. 





The dimensions of a rectangle 
20110508 

yolanda pose la question : If the length of a rectangle is 3ft less than twice its width and the area of the rectangle is 54ft^2,what are the dimensions of the rectangle? Penny Nom lui répond. 





The linear thermal expansion of steel 
20110503 

Scot pose la question : Several questions on your site deal with the linear thermal expansion of steel. Such as how much will a piece of steel grow in length if it is heated. My question is similar but I would like to know if there is a different calculation to determine how much the diameter of a round bar will grow when heated. Can you tell me how I can calculate how the diameter of .500" round steel will increase for every degree of temperature change? If a bar is raised from 60 degrees F to 120 degrees F how much will the diameter change? Robert Dawson lui répond. 





An exclusion zone around a triangle II 
20110503 

Aishwarya pose la question : A long time ago Mr gibson found an island shaped as a triangle with three straight shores of length 3km, 4km and 5km. He declared an exclusion zone around his island and forbade anyone to come within 1km of his shore. What was the area of his exclusion zone?
This question was answered but did not understand the explanation. Robert Dawson lui répond. 





(27^r^1)^2/3 
20110424 

YungJu pose la question : (27^r^1)^2/3 Penny Nom lui répond. 





Decreasing numbers 
20110413 

Hadi pose la question : A number is called a "decreasing number" if each digit in the number is less than the digit to its left.
For example, 87420 is a deceasing number. How many fivedigit
decreasing numbers are there? Claude Tardif lui répond. 





Eliminate y 
20110407 

Lynn pose la question : 2x + y = 8
y + 3z =5
z + 2w =1
5w + 3x = 9
Form three equations with y eliminated Penny Nom lui répond. 





The rate of change of the area of a parallelogram 
20110405 

Gevork pose la question : Let a parallelogram have sides of 8 and 12 and let vertex angle A be decreasing at a rate of 2degrees per minute. Find the rate of change of the area of the parallelogram when angle A equals 30 degrees. Penny Nom lui répond. 





Converting millimeters to centimeters 
20110404 

Pat pose la question : I need to convert 67 mm to centimeters how do I do this? Penny Nom lui répond. 





3% commission 
20110401 

bertha pose la question : A real estate broker’s base annual salary is $18,000. She earns 3% commission on
total sales. How much must she sell in real estate value during the year to earn
$65,000? Set up an equation and solve. Show all work to receive full credit. Round
final answer to the nearest dollar. Penny Nom lui répond. 





The rectangle is reduced to 90% of its original size 
20110331 

stephon pose la question : A rectangle has a length of 4cm and a width of 8cm.
If this rectangle is reduced to 90% of its original size what will be the new length Penny Nom lui répond. 





[(90+364) ÷ 2] x 15 = 
20110330 

ken pose la question : [(90+364) ÷ 2] x 15 = Penny Nom lui répond. 





sin x = 0.25 
20110329 

Wayne pose la question : How do you solve for x in the equation sin x = 0.25
the answer is 3.394 and 6.030 but I don't know the steps they used to calculate this Penny Nom lui répond. 





Write 3 1/5 in decimal form 
20110324 

Stephenie pose la question : converting fractions????
3 1/5 into decimal??? Penny Nom lui répond. 





6(M1/9)=55/12 
20110315 

Colleen pose la question : 6(M1/9)=55/12 Penny Nom lui répond. 





The mass of a metal box 
20110311 

Pamela pose la question : A metal block has the dimensions of 3.16 inches wide, 2.15 inches
high, 4.98 inches long. What is the volume of the block in cm^3?
What is the block's mass if the metal has a density of 5.89g/cm^3. Robert Dawson lui répond. 





Vertices and sides of a polygon 
20110304 

RINA pose la question : My questions is : would a vertices and sides of a polygon be the same number. For example, a octagon it has 8 points and 8 sides. Am i correct? Robert Dawson lui répond. 





Find the dimension of the original rectangle 
20110228 

sandra pose la question : the perimeter of a rectangle is 40 cm. if the length were doubled and the width halved, the perimeter would be increased by 16cm. Find the dimension of the original rectangle Robert Dawson lui répond. 





A camera's line of sight 
20110226 

MJ pose la question : A rocket that is rising vertically is being tracked by a ground level camera located 3 mi from the point of blast off when the rocket is 2 mi high its speed is 400mph At what rate is the (acute) angle between the horizontal and the camera's line of sight changing Penny Nom lui répond. 





Slicing a rectangular parallelepiped 
20110223 

tom pose la question : a) Pass a plane containing a vertex of a rectangular parallelepiped and a
diagonal of a face not containing that vertex to cut a pyramid from the
parallelepiped. What fraction of the volume of the parallelepiped is the
volume of the pyramid thus cut off?
b)Pass a plane through a cube of edge 8 in so that the section formed
will be a regular hexagon. Through each side of the hexagon pass two
planes, one plane containing one of the two vertices of the cube
which are farthest away from the plane of the hexagon, the other
plane containing the diagonally opposite vertex of the cube. Find the
volume of the solid bounded by these planes.
c)three of the edges of a rectangular parallelepiped that meet in a point
are also the lateral edges of a pyramid. What fraction of the parallelepiped
is this pyramid...?
you know the my only problem is how to illustrate this one...if only i
could ...can you help me....all I need is the drawing and I can do the rest
..it's fine if you'll only answer any of these but I'll be thankful if you
will do the three :).... Penny Nom lui répond. 





Triangles with perimeter 16 cm 
20110222 

Chong pose la question : How many triangles (up yo congruence) with perimeter 16 cm and whose lengths of its side are integers? Chris Fisher lui répond. 





Reversing the digits 
20110208 

rejie pose la question : if the digits are reverse , the number is 9 less than the original number.what is the equation? Penny Nom lui répond. 





Calibrating a conical tank 
20110205 

Bill pose la question : Hi, I have a round tank with tapered sides where I know the diameter at the top and bottom. Is there a formula I can use to calculate the volume by measuring from the bottom up the side (at the angle of the side) to any given point? Thanks, Bill Stephen La Rocque and Penny Nom lui répond. 





An even multiple of 27 
20110201 

parth pose la question : the 6 digit # 63x904 is an even multiple of 27 what is X Penny Nom lui répond. 





The sides of an equilateral triangle 
20110127 

Cristal pose la question : Hello :) How can i find the sides of an equilateral triangle when only given the height 10m? Penny Nom lui répond. 





Mathematics and a musical dilemma 
20110119 

rahul pose la question : how is mathematics applied in entertainment? Harley Weston lui répond. 





2x = 2+2x 
20110115 

james pose la question : 2x=2+2x can you help me find what x epauls? Penny Nom lui répond. 





The height of a lamp 
20110113 

Dorothy pose la question : I need to find the lamp height with casting shadow (base line of triangle where a boy 1.6m tall stands 3m from base of street lamp and has a 2m shadow. In other words, think of a right angle triangle with zero height starting at left, then 2m to right stands boy (1.6m high). Angle (hypotenuse) increases up to top of street lamp with 'x' height and 3m base. Penny Nom lui répond. 





The weight of a tank 
20110111 

tom pose la question : A tank, open at the top is made up of thin sheet iron 1in. thick. The internal
dimensions of the tank are 4 ft. 8in. in long ;3 ft. 6 in.in wide ;4ft 4 in. in deep
Find the weight of the tank when empty, and find the weight when full of salt
water. (Salt water weighs 64 lbs. per cu. ft., and iron is 7.2 times as heavy as
salt water) Harley Weston lui répond. 





Set notation 
20110110 

Ron pose la question : The question asked in a handout:
8k  5 < 35, keI
I believe the answer to k is 5. But what does the k e(E) I mean in this? Harley Weston lui répond. 





The third side of a triangle 
20101228 

andrea pose la question : in triangle abc, ab=5 and the area is 50cm2.If angle c 90degrees, find the length
of c. Penny Nom lui répond. 





The thermal expansion of steel 
20101220 

roger pose la question : Knowing that the coefficient of thermal expansion of steel is 6.5E06
in/in/deg F. How do you calculate the loads applied as a result of the expansion? Robert Dawson lui répond. 





A geometric progression 
20101215 

Abeth pose la question : find the value of x so that 2(x1), x+3, x will be a geometric progression. Penny Nom lui répond. 





The value after 30 years 
20101215 

Abeth pose la question : At the end of every year, the owners of a building which costs 2, 500, 000 pesos deducts 15% from its carrying value as estimated at the beginning of the year. find the estimated value at the end of 30 years. Penny Nom lui répond. 





A rectangular solid 
20101208 

ryan pose la question : Good day!
Have a question on rectangular solids. We were asked to find the dimensions of a rectangular solid, we were only given the volume of the rectangular solid, the total area, and the altitude. I tried using the volume of the rectangular solid and was able to get the area of the base, but I don't know how to get its length and its width. Hope you could help me again. Thanks! Penny Nom lui répond. 





Sales as a function of advertising 
20101208 

Adori pose la question : The sales S(in thousands if units) of a product after x hundred dollars is spent on advertising is given by S=10(1e^kx). Find S as a function of x if 2500 units are sold when $500 is spent on advertising. Penny Nom lui répond. 





Simultaneous equations 
20101205 

ryan pose la question :
Question from ryan, a student:
3 4
   = 1 (1)
x y
7 2 11
   =  (2)
x y 12 Chris Fisher and Stephen La Rocque lui répond. 





Simplify the logarithmic expression 
20101202 

Adori pose la question : Use the properties of logarithms to simplify the logarithmic expression. Log(1/250) base 5 Penny Nom lui répond. 





How many gallons of water will it take to fill a classroom? 
20101201 

deena pose la question : How many gallons of water will it take to fill a classroom that is 26 feet long by 19 feet wide and 9 feet high? How many tons of water will that be? Stephen La Rocque lui répond. 





Sides and diagonals of a polygon 
20101125 

nicky pose la question : The sum of sides of two polygons is 12 and the sum of their diagonals is 19. What kind of polygon are they? Penny Nom lui répond. 





A remainder of 3 
20101124 

khodr pose la question : find the smallest number (>3) that , when divided by 6 , 8 , 15 , and 18 , gives a remainder of 3 . Robert Dawson lui répond. 





Determine if a point is inside a cube 
20101124 

Ali pose la question : hi every one
i have a problem with cube
they told me to write a program that determine if a point is
inside a cube
so i need the equation of the cube to do the comparison.
in sphere it is easy
sqrt((xxp)+(yyp)+(zzp))<=radios
if u please could help me Robert Dawson lui répond. 





A 20" octagon 
20101119 

CHARLES pose la question : I have a 20" octagon and it has 8 parts. In inches how big is each
part. I was told each part was 5.86".The top of the octagon breaks
into 3 equal parts don't equal 20".When i did my math i thought it should be 6 5/8" which is closer
to 20"
I am trying to cut a octagon out of a 20"circle Stephen La Rocque lui répond. 





Simple interest 
20101117 

Abeth pose la question : At what simple interest rate will a sum of money triple itself in 5 years time? Penny Nom lui répond. 





A six digit number containing no zeros 
20101115 

John pose la question : Find a Six digit number containing no zeros in which the first digit is three less than the third,
the third digit is three less than the fifth,and the second digit equals the sum of the last three digits. Penny Nom lui répond. 





How far must the pitcher travel to get to the ball? 
20101104 

ken pose la question : A baseball player bunts a ball down the first base line. It rolls 35ft at an angle of 26 degrees with the first base path. The pitchers mound is 60.5 ft from the plate. How far must he travel to get to the ball. Penny Nom lui répond. 





The sides of a trapezoid 
20101103 

Bobbi pose la question : Isosceles Trapezoid base=60”; two 45⁰angles at base, two 135⁰ angles at the top, vertical distance between base & top=16”. What is the length of the top line and the two equal side lines? Penny Nom lui répond. 





The weight of some dirt 
20101103 

Maggie pose la question : I am wanting to know how many tons of dirt we r going to need to fill a basement.
The measurements we r going with r 15ftx15ftx8ft. Penny Nom lui répond. 





I have a sign size regulation I have to meet. 
20101026 

Scott pose la question : I have a sign size regulation I have to meet. The size is .6 meters squared. at first look this would be 2 ft x 2 ft.
I believe it would be larger then that. Can you confirm what the size would be in inches please. Penny Nom lui répond. 





a^(2^n) 
20101022 

Tim pose la question : I am trying to understand a^(2^n).
The hint they give is a^(2^(n+1)) = (a^(2^n))^2
I am writing a program that will solve a^(2^n) recursively but need to
understand the power before I begin.
I am currently pursuing writing (a) x (a^(2^(n1))) where the
(a^(2^(n1))) would be the recursive function call a n approaches 0.
Once n is 0, the result would be multiplied by a two more times.
Anyway, explaining these powers would be appreciated. I will most likely
complete the program before the answer but I want to understand the
logic of these powers. Thank you, Tim Stephen La Rocque lui répond. 





Powers 
20101020 

dylan pose la question : how do you write 20736 in exponential form .same for 1728 and 50625.
is there a formula to figure out how to express large know numbers in exponential form. Penny Nom lui répond. 





An exponential equation 
20101019 

Sandi pose la question :
Question from sandi, a student:
I have several questions similar to this one and was wondering if you could walk me through this one. I'm totally lost on how to do it.
Paramecia reproduce by splitting in two. In a laboratory flask, a colony of paramecia had an initial population of 500. Each day, the population of the paramecia was counted. The results are as listed.
Time (in days)Population
0500
1600
2720
3864
41037
51244
61493
71792
82150
1.)Using graphing calculator make a scatter plot of the data in table.
I think I did this part right I set my window at Xmin=0 Xmax=10 Xscl=1 Ymin=0 Ymax=2500 Yscl=100 Xres=1
2.) Determine an exponential equation to represent the population as a function of time without using a graphing calculator.I have no clue how to do this.
3.)Suppose the flask and food supply is large enough to support the trend of the population growth. Estimate the population of the colony when the time is 10 days. Penny Nom lui répond. 





Simplifying fractions 
20101013 

Alice pose la question : 14times (9divied3) + 12
______________________
18 divied (2624)
don't get this....... Penny Nom lui répond. 





Tiles on a bedroom floor 
20101007 

Rochelle pose la question : John's bedroom floor is square in shape. He used 625 tiles, with a side length of 200 mm, to tile the whole floor.
Calculate the area and dimensions of the bedroom Penny Nom lui répond. 





A division sentence for an array 
20101005 

Laura pose la question : On a math test Grace needs to look at an array and write a division sentence for the array. Grace writes 18/3=6 on her answer sheet. Describe what the array on Graces test looks like. Penny Nom lui répond. 





4√3 + 2√1/3 
20100925 

Michelle pose la question : How do you solve 4√3 + 2√1/3? Please show step by step. Penny Nom lui répond. 





Six nines 
20100916 

Steph pose la question : It's sort of one question. We have to use six nines to get the numbers 130. I got all but 22, 23, 24, and 30. Like 15 is 9+9(9+9+9)/9. Penny Nom lui répond. 





A building and a flag pole 
20100909 

paul pose la question : A flag pole and a building stand on the same horizontal level. From the point p at the bottom of the building,the angle of elevation of the top t of the flag pole is 65 degrees. From the top q of the building the angle of elevation of the point t is 25 degrees.If the building is20 meters high. Calculate the distance pt Penny Nom lui répond. 





Disposing of some concrete 
20100812 

Kathy pose la question : We are needing to dispose of concrete that we are tearing out of our
backyard and I need to figure the dimensions and weight.
I figured we have approx. 419 sq ft of concrete at 4" thick.
Could you tell me the how much that comes to in cubic ft,
cubic yards and weight. So I can get some estimates on pricing to
haul off and dispose of. thank you Harley Weston and Tyler Wood lui répond. 





A shrunken car 
20100731 

Diana pose la question : Car manufacturers have outdone themselves. They have discovered how to shrink a car to make parking easier. At the touch of a button, a car shrinks by 2 feet in the width and 4 feet in the length. The original car base is 24 square feet longer than that of the shrunken car. If the original cars length is twice the width, find the dimensions of both cars. Identify the unknowns carefully. Penny Nom lui répond. 





70 cubic meters of mulch 
20100730 

zsuzsi pose la question : i have 70 cubic meters of mulch to move and an 8 tonne truck to use
how much tonnage is to 1 square meter so that i can work out how many trips i need to make Penny Nom lui répond. 





The suspension cables of a bridge 
20100729 

Mike pose la question : what is the formula for the suspension cables of a bridge.
The towers are 200 ft above the roadway
The towers are 3400 ft apart
The cable if at 8ft in the middle of the span Robert Dawson lui répond. 





The tonnage of some gravel 
20100722 

Gregory pose la question : i have a road that is 8 miles long 20 feet wide and 4 inches deep what is the tonnage for gravel i would need Penny Nom lui répond. 





Simplify (2x)3 
20100716 

emily pose la question : how to Simplify (2x)3 Melanie Tyrer and Penny Nom lui répond. 





Converting kilograms to cubic metres 
20100716 

Ilai pose la question : I want to convert kg to cubic metre Penny Nom lui répond. 





The area of a 4 sided region 
20100714 

Cliff pose la question : If I wanted to know the square footage of an area that has four different sides and only had the length of one side and the angles at the ends of that length; could the other lengths be found if I wanted to have a total of 130,680 square feet? Robert Dawson and Tyler Wood lui répond. 





Thermal expansion of a steel beam 
20100625 

chris pose la question : If a 50 ft steel beam can expand up to 4inches when heated to 1000f
How much will a 162 ft and six inches steel beam expand under the same conditions? Robert Dawson lui répond. 





(x^3 + 11x) is divisible by 6 
20100624 

PT pose la question : Given that x is a nonzero integer,
how do you show that for all values of x,
(x3 + 11x) is divisible by 6?
I know it works but how do I answer the "all values of x" part?
Thanks in advance! Robert Dawson lui répond. 





Expand and simplify 
20100615 

Alaa pose la question : Expand and simplify
(x9)(x+2) Penny Nom lui répond. 





11 trillion divided by 309,418,000 
20100605 

Dion pose la question : I am struggling to calculate what 11 trillion divided by 309,418,000 is. Penny Nom lui répond. 





The capilano suspension bridge 
20100603 

nida pose la question : the capilano suspension bridge in north vancouver is the world's highest footbridge of its kind. the bridge is 140m long . from the ends of the bridge the angles of depression of a point on the river under the bridge are 41 degrees and 48 degrees. how high is the bridge above the river to the nearest metre Penny Nom lui répond. 





Math in the workplace: nursing 
20100524 

Taylor pose la question : How is math used in the workplace  Nurse Anesthetist? Penny Nom lui répond. 





Divisibility by 3 
20100523 

Cathleen pose la question : To math central. I have to do a maths extension question that I don't understand. At first I thought I did.
It is about the dividing by three. In one part of the question, it asks me to show that the rule of division by three does not work for 23142 with a little 5 down the bottom.
What doe base 5 mean? We first thought that the little 5 down the bottom meant multiplying y the power of five.
Can you please tell me what it means so I can finish this question? Penny Nom lui répond. 





converting y=mx+b into ax+by+c=0 and vice versa 
20100522 

Paulo pose la question : converting y=mx+b into ax+by+c=0 and vice versa Tyler Wood lui répond. 





(x+1)(x+2)(x+3)/(x+1)(x+2) 
20100519 

Nazrul pose la question : Simplify : (x+1)(x+2)(x+3)/(x+1)(x+2)
Which answer is correct:
(i) x+3
(ii) (x+2)^2(x+3)
Please help me. Harley Weston lui répond. 





A 22 litre bag of topsoil 
20100506 

Blanche pose la question : I do a fair amount of gardening when the weather permits. Just wondered if anyone call tell me what a 22 litre bag of topsoil would weigh and how to convert that. My husband says 20 lbs. I say noway I think it's more. Thanks to whomever can help me. :) Penny Nom lui répond. 





Line of sight 
20100506 

David pose la question : I live in St. Joseph, Michigan and there is an ongoing argument regarding lineofsight over the horizon.
Standing on a 200 foot high bluff here, people swear they can see the top of the Willis (nee Sears) Tower in Chicago, which is about 1653 feet high.
It is my contention that this is actually a "refracted reflection" and not directlineofsight.
So, to settle the argument, I'd sure like some simple explanation for this, even ifand I hope notI am incorrect.
David Harley Weston lui répond. 





Interest 
20100504 

RW pose la question : If you earned 55.00 for a year in your savings acct. The account pays 0.5 % interest. How much money did you initially have in the savings account. Penny Nom lui répond. 





The rejection region 
20100501 

Mong pose la question : In Tests of Hypothesis, what is the decision when the test statistic we compute from the sample information is exactly equal to the critical value? that is, we reject null hypothesis or do not reject it?
Thanks! Chris Fisher lui répond. 





A geometric progression 
20100430 

Kalyani pose la question : sum of infinite geometric progression is 9 and common ratio is 1/10
then sum up to 8 terms is? Chris Fisher lui répond. 





Commission 
20100424 

TAHIR pose la question : I want to predetermine the amount of commission on sale of my product which will be the amount that I shall have to pay .
For example, the price is $ 600and commission 5% .
1) I calculate commission on 600 @ 5% = $ 30
When added $ 600 the retail price = $ 630
2) But on $ 630, 5% commission = $ 31.50
So we make a loss of $ 1.50 .
3) Again if we add this $ 1.50 to $ 630 the price = 631.50
But the commission when calculated does not tally
and we make a loss of $ 0.075.
Please let me know how to determine the commission beforehand so that it matches our accounts. Penny Nom lui répond. 





4 + 10 + · · · + (6n − 2) 
20100421 

Lan pose la question : Find the sum 4 + 10 + · · · + (6n − 2). The answer is 3(n^2) + n. How? Penny Nom lui répond. 





Four less than three times a number is 14 
20100416 

David pose la question : My daughter has two questions that we could use some help with.
First ?
Four less than three times a number is 14
Secound?
The quotient of 15 and w Penny Nom lui répond. 





Polar coordinates 
20100414 

Lan pose la question : Given the rectangular equation (x^2)+2x+(y^2)+y=0, find the polar equation. Harley Weston lui répond. 





Counting by sevens 
20100413 

Larry pose la question : Lee counted by 7's beginning with one of the whole numbers from 1 through 7, until Lee passed 1000. If Lee counted
three of the following numbers, which number did Lee NOT count?
a. 107
b. 184
c. 534
d. 641
Robert Dawson and Penny Nom lui répond. 





6 items are taken 3 at a time 
20100412 

Kristen pose la question : Explain the three different scenarios that could occur and would result in the following number of outcomes when 6 items are taken 3 at a time. Give reallife examples.
a. 63 = 6 x 6 x 6 = 216 possibilities
b. 6! / (6  3)! = 6 x 5 x 4 = 120 possibilities
c. 6! / (6  3)! 3! = 20 possibilities Tyler Wood lui répond. 





A cube with twice the volume 
20100411 

Woojin pose la question : From a given cube create another cube with twice the volume.
the cube: 5cm each. Tyler Wood lui répond. 





Sample size 
20100329 

Rae pose la question : What sample size was needed to obtain an error range of 2% if the following statement was made? "75% of the workers support the proposed benefit package. These results are considered accurate to within + or  2%, 18 out of 20 times. This seems like a straight forward question but I'm getting it wrong. Could you please help me out even just the set up would be appreciated so I can see if that's where I'm going wrong. Thanks Harley Weston lui répond. 





A radio tower 
20100326 

Alex pose la question : The height of a radio tower is 450 feet, and the ground on one side of the tower slopes upward at an angle of 10 degrees. How long should a guy wire be if it is to connect to the top of the tower and be secured at a point on the sloped side 110 feet from the base of the tower? Harley Weston lui répond. 





What is 8.6597 divided by two thirds? 
20100322 

patsy pose la question : what is 8.6597 divided by two thirds Penny Nom lui répond. 





A quadrilateral with 4 known sides and 1 known angle 
20100319 

samuel pose la question : Name: Samuel
Status: Student
I have a quadrilateral with 4 known sides and 1 known angle, and I'm trying to evaluate the other angles of my quadrilateral.
By the law of cosines, I can easily find my opposite angle (using the diagonal as a basis for the equation).
However, to find the two remaining angles, I have found no other way so far than to use the other diagonal, which can be found with the equation attached (from geometry atlas).
Is there any simpler way? Robert Dawson and Harley Weston lui répond. 





How many zeros? 
20100318 

jeff pose la question : 1 light yr is 6,500 billion miles, the galaxy "Andromeda" is 2,500,000 million light yrs, how many zeros are in this equation ? Robert Dawson lui répond. 





Repeating Decimal 
20100314 

Gerald pose la question : Find the 1987th digit in the decimal equivalent to 1785/9999 starting from decimal point. Can you give us a short but powerful technique in solving this problem? thanks so much.. Chris Fisher lui répond. 





A 14 side well house cover 
20100312 

Kenneth pose la question : I am 35 yr I am wanting to build a well house cover. I'm trying to figure out how long the pieces need to be and what angle they need to be for a 4 ft dia with 14 side well house. I would love an answer but would also like to know how to figure it in the future. Thanks Kd Harley Weston lui répond. 





The nth derivative of x^(n1) log x 
20100310 

shambodeb pose la question : This is a successive differentiation problem by Leibnitz theorem
If y = x^{n1} log x ; Proof nth derivative y^{(n)} = (n1)!/x Harley Weston lui répond. 





The side length of a square 
20100308 

tara pose la question : am trying to help my brother's daughter in maths, tomorrow she has maths exam
1. Area of sq. picture is 441 sq.cm what is the length of its side. Penny Nom lui répond. 





0.999 ^ (500) 
20100307 

debra pose la question : I just need to know how to solve the following problem without using a calculator: .999 ^ (500). I know the answer is .606, I just want to do it by hand since I can't use a calculator on my test. Penny Nom and Claude Tardif lui répond. 





The dimensions of a rectangle 
20100303 

Kirsten pose la question : A rectangle is twice as long as it is wide. Its area is 128 square meters. What are the dimensions of the rectangle? Tyler Wood lui répond. 





The test for some disease is 99% accurate 
20100224 

baaba pose la question : Assume that the test for some disease is 99% accurate. If somebody tests positive for that disease, is there a 99% chance that they have the disease? Chris Fisher lui répond. 





Fahrenheit and celcius 
20100219 

Carol pose la question : Zack is packing for a trip to Scotland. He read that the average temperature in the Summer is 18degrees C during the day, and 7 degrees during the night. What is the difference between the high and low temperatures in degrees Fahrenheit? (F=9/5C=32) Lorraine Dame lui répond. 





Square poles 
20100216 

Steve pose la question : If 1 pole=16.5', and you have an area that is 146 sq. poles, how many sqaure feet would you have?
I calculate that to be 146(16.5)X146(16.5)=5,803,281 sq. feet Is that correct? I am told I need to divide by 146, which makes the answer 39,748. I do not understand why I need to divide by 146.... Penny Nom lui répond. 





4digit positive numbers 
20100215 

marjon pose la question : Find the sum of all the 4digit positive numbers with no zero digit. Penny Nom lui répond. 





The dimensions of a flag 
20100215 

dawn pose la question : a state flag was twice as long as it was wide and had an area of 288 sq inches, what were its, dimensions
Thanks Penny Nom lui répond. 





The difference of the two numbers 
20100215 

Steve pose la question : The difference of the two numbers 'abcdef ' and ' fdebca ' is divisible by 271. prove
that b = d and c = e. Claude Tardif lui répond. 





Can a line segment curve over two planes? 
20100214 

Graham pose la question : I am working on a math fair project.
Can a line segment curve over two planes?
Such as, if I had a three dimensional L bracket and I drew a line segment
on it with a marker starting on the bottom of the L and had it curve
around the corner and up the top, would it still be considered one line
segment? Or is that two line segments?
Is there a rule that a line segment can only occupy one plane?
Thank you.
Graham Chris Fisher lui répond. 





A sequence 
20100207 

Shalev pose la question : hi,
i had a job interview yesterday. it had mathematical questions. couldn't solve 1. i m obsessed with it. please find out what the answer is..
it goes like this:
2,4,5,5,8,6,_,_,14,8
thank u very much Claude Tardif lui répond. 





I want to convert my glaze percents into grams 
20100205 

linda pose la question : I am a potter. I want to convert my glaze percents into grams.
ex. 20% of 20 lbs would equal how many grams?
is there a formula to figure this? Penny Nom lui répond. 





An impossible isosceles triangle 
20100131 

Hailey pose la question : An isosceles triangle has one angle that measures 50 degrees and another that measures 70 degrees. Why can't this triangle be drawn? Penny Nom lui répond. 





Solving a triangle 
20100125 

Paige pose la question : how do i solve a triangle with one angle of 73 degrees,
one angle of 32 degrees, and one side of 23cm? Harley Weston lui répond. 





A sequence 
20100122 

brahmaji pose la question : 0 7 26 63 _ 215 342 fill the blank? find the missing number Robert Dawson lui répond. 





The volume of a silo 
20100121 

heather pose la question : The height of the silo is 30ft and the face that rests against a barn is 10 ft wide. If the barn if 5 ft from the center of the silo what is the capacity of the silo? Penny Nom lui répond. 





Area in square meters 
20100120 

Carla pose la question : A football field is 120 yd long and 50 yd wide. What is the area of the football field, in square meters? Penny Nom lui répond. 





How fast am I walking? 
20100110 

KEVIN pose la question : IF I WALK 3 MILES IN 28 MINUTES, HOW FAST AM I WALKING? Penny Nom lui répond. 





The intervals where the function is positive and negative 
20100110 

Ron pose la question : Hello
I'm trying to find out the intervals where the function is positive and negative.
It's for a polynomial function y= (x+2)^2 (x2) and y= (x+1)(x+4)(x3)
I have tried the right and left side of each xintercepts, but I still don't understand the
results
thank you for your help Penny Nom lui répond. 





A pair of simultaneous equations 
20100109 

Yumiko pose la question : Solve the following pair of simultaneous equations.
x^2 4x = y^24
3y=2x  3 Penny Nom lui répond. 





Linear programming using the Simplex Method 
20091228 

William pose la question : A gold processor has two sources of gold ore, source A and source B. In order to keep his plant running,
at least three tons of ore must be processed each day. Ore from source A costs $20 per ton to
process, and ore from source B costs $10 per ton to process. Costs must be kept to less than $80 per day.
Moreover, Federal Regulations require that the amount of ore from source B cannot exceed twice the
amount of ore from source A. If ore from source A yields 2 oz. of gold per ton, and ore from source B
yields 3 oz. of gold per ton, how many tons of ore from both sources must be processed each day to
maximize the amount of gold extracted subject to the above constraints?
I need a linear programming solution or algorithm of the simplex method solution.
Not a graphical solution. Thanks. Janice Cotcher lui répond. 





StefanBoltzmann Law 
20091228 

florence pose la question : Hi
I have a college tutor and we are stumped with this question.
Assuming a filament in a 100 W light bulb acts like a perfect blackbody, what is the temperature of the hottest portion of the filament if it has a surface area of 6.3 X 10^5 m^2? The StefanBoltzmann constant is 5.67 X 104 W/(m^2 X K^2.\
Thank you for your help. If you can only answer one question per day please answer this one and guide me through a solution. Janice Cotcher lui répond. 





Finding Density Given Volumetric Thermal Expansion Coefficient 
20091226 

florence pose la question : Hi
Please help me to apply the formula for this problem. The coefficient of volumetric for gold is 4.20 X 10^5 C degrees. The density of gold is 19,300 kg/m^3 at 0.9 C degrees. What is the density of gold at 1050 degrees C.
Could you please explain how to get the solution of 18,500 kg/m^3
Thank you for your help
Florence Janice Cotcher lui répond. 





Triangles on a base of 2.4 meters 
20091226 

Allan pose la question : Please,How do I calculate the height of a triangle when I only know the width of the base line,It is 2.4 mtrs. Thankyou very much. Penny Nom lui répond. 





Finding Specific Heat of a Substance 
20091226 

erin pose la question : Hi
2 kg metal requires 1.00 X 10^4 J of heat to raise its temperature from 20 degrees C to 40 degrees C. What is the specific heat capacity of the metal? Janice Cotcher lui répond. 





A trig question 
20091215 

A trig question pose la question : Hey, my name is Candle
I'm in academic math10 and am stuck on my trig... one question I thought I had right because i used the cosine law I got wrong and can't figure out why... here's a copy of the question. (i guessed it was D... but my teacher said it's B)
Thanks
Candle Robert Dawson lui répond. 





Energy in calories 
20091215 

Josephine pose la question : A soft drink manufacturer claims that a new diet soft drink is now "low Joule". The label indicates that the available energy per serving is 6300 J. What is the equivalent of this energy in calories? (1 Calorie=1000 cal) Robert Dawson lui répond. 





A telephone pole on a slope 
20091214 

Marissa pose la question : A 10 meter telephone pole casts a 17 meter shadow directly down a slope when the angle of elevation of the sun is 42 degrees. Find the angle of elevation of the ground. Its a law of sines problem. Penny Nom lui répond. 





A number base that's not a positive integer 
20091211 

Nick pose la question : Is it possible for a number to have a base that's not a positive integer?
Base 1 gives a result that's meaningless but possible. I have no concept of a base 0, a negative base, or a fractional base, never mind any other base. I think there isn't any base that's not a positive integer, but, knowing that math keeps jumping ahead and sometimes has inventions before anyone knows how to exploit them, I think I'd better ask.
Thank you.
Nick Robert Dawson and Claude Tardif lui répond. 





How fast is the distance between the two cars decreasing? 
20091208 

Jenny pose la question : Two cares are on a collision course toward point P. The paths of the two cars make a 30 degree angle with each other. The first car is 40 km from P, and traveling toward P at 16 km/hour. The second car is 50 km from P, traveling at 20 km/hour. How fast is the (straight line) distance between the two cars decreasing. (Hint: Law of Cosines) Harley Weston lui répond. 





Simplifying a quadratic expression 
20091207 

Sabbie pose la question : Hi, I need help solving this equation for my physics homework,so I can solve the quadratic equations for x and y.
I've derived the following equations from the information provided in the question.
2a+3b = 4  1
2a^2 + 3b^2 = 62  2
a=2(3/2)b is substituted into equation 2.
so, i get
2 (2(3/2)b)^2 + 3b^2 = 62
this is where the problem begins. i cannot work through this to get to the correct quadratic equation
5b^28b36=0
I can't seem to be able to figure out where I keep going wrong. I would really appreciate it if you could give me a stepbystep breakdown of the workout.
thanks! Penny Nom lui répond. 





(9  x^2)/(x  3) 
20091204 

Sandy pose la question : 9x^2/x3
I need to know how to solve this.
Thanks Penny Nom lui répond. 





Milliliter conversion 
20091129 

Jan pose la question : I am trying out a new bath salt recipe for one of my clients that has little children. Here then is the question, the recipe for color changing bubble bath calls for 0.15ml dry FD&C color. Since the recipe came from Australia, I have not a clue of how to change this into USA measurments Penny Nom lui répond. 





Sixletter words 
20091124 

christine pose la question : How many sixletter words (not necessarily an English words) are there in which exactly three of the letters are z's? Claude Tardif lui répond. 





Solving two equations, one with a square root 
20091123 

kacie pose la question : y = square root of x+3
x4y = 7
im having trouble with this problem...i have to find where they intersect. Harley Weston lui répond. 





A simplification 
20091121 

Lou pose la question : In the following problem, [(7)/(x+2)][(x+8)/(4x^2)]+[(3x2)/44x+x^2)]
what steps do you use to convert the middle portion to become +[(x+8)/(4+x^2)]?
The answer to the problem is supposed to be (11x^218x+8)/(x+2)(x2)^2 Penny Nom lui répond. 





Three angles and one side of a triangle 
20091116 

Esther pose la question : How do i find the sides of an acute triangle if i know the angels are 60,45,75 and i only know one side which is 10? Thanks! Penny Nom lui répond. 





Two similar pentagons 
20091116 

louis pose la question : The lengths of five sides of a pentagon are 1,3,5,7,and 12 units. If the length of the longest side of a similar polygon is 18 units, find the perimeter of the larger pentagon. I think I figured it out Not sure though. Penny Nom lui répond. 





The line through D(4, 0) and E(2, 6) 
20091116 

Rogerson pose la question : The point F is on the line through D(4, 0) and E(2, 6) so that DF=4DE. Find the coordinates of F. Penny Nom lui répond. 





A drawing of a baseball diamond 
20091109 

Beth pose la question : My husband has a drawn diagram on a piece of paper of a baseball diamond. He knows that on the paper 1 1/16" (1.6875") = 90 actual feet. How do we calculate how many feet 5 7/8" on the paper would be? Penny Nom lui répond. 





3x^33x3 and 3x+6 
20091104 

spencer pose la question : My question is 3x^33x3 devided by 3x+6 Penny Nom lui répond. 





Density of dirt and gravel 
20091026 

ken pose la question : if digging a load of dirt and gravel in mining how many yards of material to the ton thanks Penny Nom lui répond. 





Grams per square meter 
20090930 

MANISH pose la question : how to calculate gsm given kg of 144 sheets and size in inches
example 28" x 22" & 16.3 kgs = ?gsm (of 144 sheets) Penny Nom lui répond. 





Sawdust 
20090929 

joel pose la question : What is the density of saw dust Harley Weston lui répond. 





Grams to percent 
20090920 

brandy pose la question : how do you convert 1.5 grams to a percent Stephen La Rocque lui répond. 





A sequence 
20090919 

Oliver pose la question : I am struggling to work out the missing terms in the following sequence:
1, 3, _, 7, 11, 18, _ Chris Fisher lui répond. 





Repeating decimal to fraction 
20090918 

joan pose la question : how can i answer it easily to convert terminating decimal to fraction?
example of this is that, convert ...143143143... to fractional form Robert Dawson lui répond. 





Quotient 
20090914 

Jala pose la question : What is a quotient and what are the instructions for one? Penny Nom lui répond. 





Simplify 
20090904 

Sarah pose la question : How do you simplify:
(x4)^3? Robert Dawson lui répond. 





Simultaneous equations 
20090828 

onias pose la question : solve 3/a  2/b = 1/2 , 5/a + 3/b = 29/12 Robert Dawson lui répond. 





How do you convert cents/mile to dollars / hour? 
20090826 

seanna pose la question : how do you convert cents/mile to dollars / hour Penny Nom lui répond. 





A paper towel roll 
20090819 

Jeff pose la question : I am making a spiral tube with paper that is 2" in dia. and 102" long
I will be using paper that is slit 3" wide how many lineal feet of paper will
I need to to cover the 102"
I will be using 3 rolls of paper that will over lap the other by half to make
a hard tube (paper core) in a roll of paper towels
Thanks Jeff Penny Nom lui répond. 





How do i convert 6 feet into yards? 
20090814 

taylor pose la question : how do i convert 6 feet into yards????????????????? Robert Dawson lui répond. 





Fitting the curve y=a*exp(b*x)+c 
20090812 

aika pose la question : Could one show me the complete algorithm and formula for finding the coefficients (a,b, and c) in exponential regression model
y=a*exp(b*x)+c Robert Dawson lui répond. 





Gravel in an aquarium 
20090809 

Bev pose la question : Hi...I worked this part out, but want to know how many kilograms of gravel I will need...thanks
Bev
Cylinder shape.
A cylindrical shape that has a radius of 82 centimeters and a depth of 7 centimeters has a volume of:
Volume
= 0.14787 cubic meters
= 147870 cubic centimeters
= 0.1934 cubic yards
= 5.2219 cubic feet
= 9023.5 cubic inches
= 39.063 U.S. gallons
= 147.87 liters
* calculations accurate to 5 decimal places of precision Harley Weston lui répond. 





Eye Height Level Found from Visual Angle 
20090807 

Jolie pose la question : Hello,
I am trying to figure out what height from the ground a person's eyes are if they have a 12 degree visual angle to a screen that is 58cm away from their eyes?
Thank you. Janice Cotcher lui répond. 





Dimensions 
20090729 

Deborah pose la question : The blueprint for landscaping a yard has a scale of 1/2" to 1 foot. If the blueprint is a rectangle 18 inches by 22 inches, what are the dimensions of the yard? Robert Dawson lui répond. 





x^3+1/x^3=18*sqrt(3) 
20090708 

Nazrul pose la question : If x^3+1/x^3=18*sqrt(3) then how can I evaluate the value of x+1/x?
Thank you for your help. Robert Dawson lui répond. 





The sides of a triangle 
20090708 

Susan pose la question : The second side of a triangle is 5ft more than the length of the first side. The third side of the triangle is 10ft less than the length of the first side.
The perimeter of the triangle is 61ft. Find the lengths of each side of the triangle.
Thank you so much! Penny Nom lui répond. 





Simultaneous Equations 
20090706 

Mukulu pose la question : Solve the equation simultaneously X/5=(Y+2)/2= (Z1)/4 ……………….eqt 1
3X+4Y+2Z25=0 ………………eqt 2 Janice Cotcher lui répond. 





Coefficient thermal expansion of steel 
20090629 

roshni pose la question : Coefficient thermal expansion of steel is 0.00000645/in/in/deg F if F was C(celcius) then what is the answer Robert Dawson lui répond. 





The dimensions of a cuboid 
20090624 

laura pose la question : a cuboid has the surface area of 842 cm2, can you work out the dimensions? Robert Dawson and Harley Weston lui répond. 





Cubic meters of gravel in a 7 ton lorry 
20090621 

Jackie pose la question : I have to transport gravel in a 7 ton lorry and I know how many cubic meters of gravel I need, but I need to know how many cubic meters of gravel a 7 ton lorry can hold.
Thanks, Jackie Penny Nom lui répond. 





Two questions from math class 
20090618 

Con pose la question : Hello,
My name is Con and my son is required to answer the following questions for his maths class.
He has attempted Q1 through trial and error and has found the answer to 72453. Is this correct?
He has attempted to draw the triangles described in Q2 in a number of ways and has found that BE can not equal ED and is dependent of angle BAC. Therefore, he claims that the triangle can not be drawn/practical. Is this correct or is there a slolution?
Q1.
Digits 2, 3, 4, 5 and 7 are each used once to compose a 5digit number abcde such that 4 divides a 3digit number abc, 5 divides a 3digit number bcd and 3 divides a 3digit number cde. Find the 5digit number abcde.
Q2.
Let ABC be a triangle with AB=AC. D is a point on AC such that BC=BD. E is a point on AB such that BE = ED = AD. Find the size of the angle EAD.
Con Chris Fisher lui répond. 





Successive differences 
20090618 

Jonathan pose la question : I'm trying to find the next number sequence for this equation: 1 11 35 79 149 251, my problem is that I worked it out and ended up with a single number 17. What am I doing wrong. Thank you for any help. Robert Dawson and Penny Nom lui répond. 





Thermal Expansion of Steel 
20090617 

Ken pose la question : Hi there, We are rollforming steel roofsheeting in 65M lengths and the =
question of linear expansion has cropped up.I would like to know what =
the expansion rate of this sheet would be over a temperature rise of say =
40degree F.in mm per Meter or whatever the norm is. The sheet is 0.53mm =
thick and is 700mm in width,I hope this is sufficient info to enable you =
to do your calculation.Many thanks, in anticipation.
Ken Janice Cotcher lui répond. 





Divisibility 
20090617 

Sophia pose la question : Hello
Please help my son with the solutions to the following:
a) Determine the remainder when 2^2009 + 1 is divided by 17;
b) Prove that 30^99 + 61^100 is divisible by 31;
c) It is known that numbers p and 8p^2+1 are primes. Find p.
Again, your assistance is greatly appreciated.
Thanks
Sophia Robert Dawson lui répond. 





Vectors and the Law of Cosine 
20090608 

lauren pose la question : once 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 Janice Cotcher lui répond. 





Initial Velocity of a Car Plunging Off a Cliff 
20090607 

Mimi pose la question : A car fails to take a sharp turn on a flat road and plunges off a cliff. The car lands 65m horizontally and 43m vertically from where it left the edge of the cliff. How fast was the car travelling? Stephen La Rocque lui répond. 





The dimensions of a rectangle 
20090530 

Linda pose la question : A rectangle has a perimeter of 38 feet & an area of 48 square feet. What are the dimensions of the rectangle? Stephen La Rocque lui répond. 





A sequence 
20090526 

Jay pose la question : what is the equation that would give me the next 3 numbers in this progession: 0,1,5,14,20 Stephen La Rocque lui répond. 





The quotient of 5/8 divided by7/4 
20090525 

tammy pose la question : find the quotient of 5/8 divided by7/4 Stephen La Rocque lui répond. 





The Smythe family lot 
20090524 

Shrima pose la question : We must determine the size of the lot. The Smythe family lot is 235ft
across the front and 212ft down the side and 254ft down the other side.
The sides of the lot are parallel to each other and perpendicular to the front.
The size of the lot is two dimensional measure therefore you need to find
the areaenclosed by the lot line.
Question:
What is the size of the Smythe lot including the unit? Penny Nom lui répond. 





The position of the fulcrum 
20090523 

jim pose la question : I think I need a formula. I need to know how far an object will be lifted.
A beam is 246 inches long on one side of the fulcrum, and 41 inches on the other side,
if I push down 36 inches on the long side of the beam, how much will the short side move up? Stephen La Rocque lui répond. 





A geometric progression 
20090516 

sweta pose la question : find the ratio of GP if the first term is 1 and the sum of third and fifth term is 90. Penny Nom lui répond. 





Unit Conversion for Force and Mass 
20090508 

Ray pose la question : Good Day! I was confused about lbm and lbf and slug. I knew that lbm is a unit
for mass and lbf is a unit for weight. my problem is some books follow this
relationship where lbf=(lbm times the gravitational pull) which is 32.2 ft/(s^2)
while other books treat lbm=lbf. other books also treat lbm=(lbf times 32.2)...
which is correct?
Is 1kg=2.205 lbm or 1kg=2.205lbf?
Is 1BTU=778.16 lbfft or 1BTU=778.16 lbmft?
what is the relationship of slug on these two, lbm and lbf? Janice Cotcher lui répond. 





Cubic feet and cubic yards 
20090508 

TJ pose la question : 21 bags at 2 cubic feet per bag.
How many yards would that be? Penny Nom lui répond. 





The dimensions of a toy chest 
20090507 

charlotta pose la question : My son needs to find the 3 dimensions of a toy chest that has to have a volume of 24 cubic feet can you show how to get the answer Penny Nom lui répond. 





8.55 acre of land 
20090506 

Mary pose la question : I have a deed with 8.55 acre of land, how much land is that .55 ? Robert Dawson lui répond. 





5^2= 25 
20090506 

tracy pose la question : show how to perform this calculation and why
5^2= 25 Robert Dawson lui répond. 





How do you convert 1248 to base 6? 
20090502 

Tamara pose la question : How do you convert 1248 to base 6? Penny Nom lui répond. 





Decimeters and centimeters 
20090430 

Jeannette pose la question : I cannot convert because of a question that throws me off. For example, A mother African elephant avg's 250 dm in height. A newborn baby African elephant avg's 89cm in height. How many cm shorter is the baby African elephant than its mother? Which one do I convert first? in order to subtract the number from the baby? Penny Nom lui répond. 





The volume of 3D figures 
20090429 

Serena pose la question : What is the formula for finding the volume of 3D figures Robert Dawson lui répond. 





The integral of a to power x squared 
20090428 

JIM pose la question : WHEN I ATTENDED U.OF T. (TORONTO ) MANY YEARS AGO
WE WERE TOLD THE FOLLOWING INTEGRAL COULD NOT BE
SOLVED : a to power x squared . is this still true ?
CURIOUS , JIM Robert Dawson lui répond. 





An odd shaped lot with a curve to it 
20090425 

Chris pose la question : Hi  Im trying out to figure out how to calculate the size of an odd shaped lot with a curve to it.
Chris Harley Weston lui répond. 





2+6+12+20+30+42 
20090424 

fredy pose la question : what is the sigma notation for the series 2+6+12+20+30+42? Stephen La Rocque lui répond. 





Miles per hour and feet per second 
20090422 

mary pose la question : A car traveling at 60 miles per hour, how many feet per second has it traveled? Robert Dawson lui répond. 





Percent increase from a negative number to a positive number 
20090421 

Brian pose la question : I have no problem calculating year over year net profits but am having trouble when it comes to a negative.
2007 Net Profit = 110,333.00
2008 Net Profit = 66,054.00
Brian Harley Weston lui répond. 





Two regular hexagons 
20090421 

niko pose la question : Two regular hexagons are ____________ similar. Stephen La Rocque lui répond. 





Two similar rectangles 
20090419 

Alyssa pose la question : The ratio of the lengths of corresponding sides of two similar rectangles is 3:5. the small rectangle has an area of 36 square centimeters. What is the are of the large rectangle? Penny Nom lui répond. 





A foursided lot 
20090412 

Robert pose la question : back of property is 137' across,with an angle of 122deg.on the left side and an angle of 140 deg. on the right side,the left side is 123' and the right side is 93' long,the left front is 130 deg. and the right front side is 150 deg. and the front of the property measures 78' Harley Weston lui répond. 





A fraction in its simplest form 
20090402 

Michael pose la question : I'm in 4th grade and need to express decimals as a fraction in its simplest
form. Is there a step by step method to figure out?
ex 0.64 = 64/100 = ? Robert Dawson lui répond. 





Thirtytwo divided by 3 
20090402 

Shelly pose la question : x = 32/3
x = 10 2/3 Divide 32 by 3: 32 / 3 = 10 R2.
What I don't get is why is it that 10 with a remainder of 2 ( 10 R2 ) equals 10 2/3? shouldn't it be 10 2/10 ????? Robert Dawson lui répond. 





A spherical Tootsie Roll Pop 
20090401 

Tracy pose la question : A spherical Tootsie Roll Pop you are sucking on is giving up volume at a steady rate of .8 ml/min. How fast will the radius be decreasing when the Tootsie Roll Pop is 20 mm across? Harley Weston lui répond. 





Four identical lots 
20090330 

Marina pose la question : I really want to know the answer to this problem for my 6th grade son. I've already sent this question with the drawing but I couldn't send it correctly. I hope this one will pass through.
Q: Divide evenly and identical the figure representing a lot, into four for the 4 siblings. I've sent a figure drawing as attachment. I will describe this in case it will not reach you: its a square divide into 4 triangle and 1 triangle is taken out living a letter M figure and
this letter M figure is the one that will be divided.into 4 even and identical parts.
Marina Claude Tardif lui répond. 





Adding in base six 
20090329 

Lucy pose la question : If you are working in base 6,
what do you have to add to 4(base 6) to get 10(base 6)???? Penny Nom lui répond. 





Subdividing a foursided lot 
20090327 

kannan pose la question : i have a 1.5 acre land having four sides
AB=64.8 meters
BC=94.2 meters
CD=54.4 meters
DA=127.2 meters
angle at D is 90
the side AB (frontage)is road facing i want to split the plot in to two halves
having same almost area and almost equal frontage, kindly help me, if possible
explain with drawing.
Regards
Kannan Harley Weston lui répond. 





Dividing by fractions 
20090325 

Mitch pose la question : 2 divided by 2/3 = ?? Penny Nom lui répond. 





Comparing positive and negative fractions 
20090324 

Christyrose pose la question : Hello. I am a sixth grade math student and i need help on how to compare negative and positive fractions.
Here is is:
3/4 2/3 7/10 5/6
I'm not sure how to do the negative parts because i was absent for a couple days. Thank you!
Christyrose Penny Nom lui répond. 





Conversion factor 
20090323 

kab pose la question : Would like to photocopy a Landscape Design. What is the Conversion Ratio or magnification required to convert 1" = 10 feet to 1/4" = 1 foot? Harley Weston lui répond. 





A rectangular open box 
20090321 

tina pose la question : An open box is to be made from a rectangular piece of tin by cutting two inches squares out of the corners and folding up the sides. The volume of the box will be 100 cubic inches. Find the dimensions of the rectangular piece of tin. Stephen La Rocque lui répond. 





A 20 foot piece of pipe 
20090319 

chris pose la question : How many 8 inch pieces can you get from a 20 ft. piece of pipe? Penny Nom lui répond. 





0.0007 as a percent 
20090318 

Shelly pose la question : I need to know how to divide 0007 by 100 and soon! and I have no idea how I can get 100 to go into a number like that! here's the question this problem originated from:
change the decimal into a percent:
0.0007 _________
How do I change THAT number into a percent?
How do I change 12.455 and 92.348 and 29.005 into percents as well? I know how to change numbers like 0.6 and 0.70 into percents but not the numbers I told you I'm having problems with. Please someone explain this to me and also please focus mainly on the first number I asked about but don't forget the others please. Please reply ASAP I need to know this in about a week or less! Penny Nom lui répond. 





The sides of a parallelogram 
20090317 

Sami pose la question : If ABCD is a parallelogram, prove that line AB is congruent to line CD. Clearly state your reasons and conjectures. Penny Nom lui répond. 





An impossible trig problem 
20090314 

Alisha pose la question : If csc theta = 3 and sec theta = square root of 3, what are the values of tan theta and cos^2 theta? Harley Weston lui répond. 





Related rates 
20090314 

Jeevitha pose la question : The side of an equilateral triangle decreases at the rate of 2 cm/s.
At what rate is the area decreasing when the area is 100cm^2? Stephen La Rocque lui répond. 





A polyhedron 
20090310 

Mollie pose la question : Hi, my name is Mollie and I'm in 5th grade. Here's the math problem I have for homework tonight:
"Larissa made a model of a polyhedron using 8 pieces of clay for the vertices and 18 straws for the edges. What type of
polyhedron did Larissa make?"
Thanks. Penny Nom lui répond. 





Related rates 
20090309 

Megan pose la question : A plane flying with a constant speed of 330 km/h passes over a ground radar station at an altitude of 3 km and climbs at an angle of 30°. At what rate is the distance from the plane to the radar station increasing a minute later? Harley Weston lui répond. 





What percent commission does Aaron earn? 
20090309 

Jerry pose la question : Aaron works part time as a salesperson for an electronics store. He earns $4.75 per hour plus a percent commission on all of his sales. Last week Aaron worked 20 hours and earned a gross income of $143.75. If his total sales for the week were $1,500, what percent commission does Aaron earn? Penny Nom lui répond. 





The sides of a triangle 
20090307 

felicia pose la question : ona map, tannersville, chadwick, and barkersvile for a triangle. Chadwick is
70 miles from Tannersville and Barkersville is 90 miles from Tannersville. Which is a
possible distance between Chadwick and Barkersville?
a. 5miles
b. 10 miles
c. 150miles
d. 200 miles Harley Weston lui répond. 





The amount of material remaining on a reel 
20090304 

James pose la question : Question from james:
I am after a standard calculation so that after each usage of the Reel I can get the Remaining Quantity in kilos left on the roll
below is an example of roll
THICKNESS: 30 MICRON
REEL WIDTH: 7.5 CM
REEL DIAMETER: 76 CM
REEL WEIGHT: 7.13 KILOS
The core centre has a 9cm diameter, the weight of the roll is excluding the core , and after each use the diameter of the role is measured.
I am a factory supervisor working on project and need this calculation info for template.. Thanks James Harley Weston lui répond. 





A shape with 10 sides 
20090303 

Sandra pose la question : One of my son's math questions is as follows:
Suppose I have a shape with 10 sides. I choose a vertex then draw lines to the other vertices that dont share sides with the first vertex. How many vertices will that be and why? Penny Nom lui répond. 





The area of a 5sided lot 
20090302 

Linda pose la question : I have a problem I'm hoping you can provide some help with. When I check the property information for our home on our District of North Vancouver website, it shows that our property is supposed to be 1146.99 Square Metres. Yet another property which has identical measurements is listed as having 1173.7 Square Metres. I would like to figure out who is correct. Harley Weston lui répond. 





An array with 2 more rows than columns 
20090228 

Mario pose la question : Write a division sentence modeled by an array that has 2 more rows than the number in each row. Penny Nom lui répond. 





Simplify the square root of 125 x^2 
20090227 

Ashley pose la question : √125x²
How do you simplify this equation assuming that variables can represent any real number? Robert Dawson lui répond. 





Triangles within triangles 
20090224 

Mari pose la question : a large shaded triangle changes each day with a white triangle appearing
in the center of each shaded one. If this pattern continues, how many white
triangles will be there on the 6th day? On the 6th day, what fraction of
the large outer triangle will be white?THANKS! Robert Dawson lui répond. 





Augmented matrix: independent, dependent, or inconsistent? 
20090223 

Anna pose la question : Perform row operations on the augmented matrix as far as necessary to determine whether the system is independent, dependent, or inconsistent.
x + y + z = 11
x  y + 3z = 5
2x + 2y + 2z = 15 Harley Weston lui répond. 





Pressure at Given Depth 
20090222 

Tamara pose la question : A sea is 3km deep. The average density of sea water there is 1020 kg/m^3. What is the water pressure at the bottom? Janice Cotcher lui répond. 





Find the resultant of this displacement pair 
20090222 

katydidit pose la question : Find the resultant of this displacement pair:
500 miles at 75 degrees east of north and
1500 miles at 20 degrees west of south.
How do I graph this and how do I solve this problem? Penny Nom lui répond. 





What deminsions should my box be? 
20090219 

Mary pose la question : My item is 57cm x 36cm x 6cm and I want to put 20 items is 1 box. What deminsions should my box be? Stephen La Rocque lui répond. 





Angle of depression 
20090218 

Meeka pose la question : An aircraft flying at an altitude of 2000m is approaching an airport.
If the angle of depression of the airport is 5 degrees, what is the distance from the plane to the airport measured along the ground?
Round your answer to the nearest tenth of a kilometer. Robert Dawson lui répond. 





Miles per hour to kilometers per second 
20090217 

Tamara pose la question : If a car goes 60 miles in an hour how many kilometres will it go in a second? Penny Nom lui répond. 





Rent and a commission 
20090217 

cliff pose la question : a landlord receives $95.00 rent 5% commission was paid to get to $95.00 what was the original number. The answer is obvious but what is the formula. Thanks. Cliff Penny Nom lui répond. 





The sides of a polygonal building 
20090213 

mark pose la question : length of sides of an 18 ft.diameter bldg
i need to find out if i should build an octagon or decagon to keep the
sides of the bldg at 8ft or less. how do i figure the length of the sides
of each? Penny Nom lui répond. 





Can you convert numbers with units to percents? 
20090212 

Kenneth pose la question : To change a number to a percent, move the decimal two places to the right and add a percent sign.
For example, 0.35875 = 35.875%.
If the number has a dollar sign or some other kind of unit, for example, pounds, feet, etc. how is the number converted to a percentage.
For example, change $0.35875 and 0.75 lbs. to a percentage. How is this done. I have never seen $35.875% or 75 lbs.% before. Robert Dawson and Harley Weston lui répond. 





Cubic feet gas to grams of gas 
20090211 

tim pose la question : I was trying to convert cubic feet gas to grams of gas. Is there a formula to complete this task? Robert Dawson lui répond. 





Cubic centimeters and ounces 
20090206 

Dawn pose la question : 1 syringe contains 5.5cc of medicine & cost $13.50
1 2 oz bottle of medicine cost $17.50
How many cc's in 2 oz, & which is the better deal? Stephen La Rocque lui répond. 





A 306090 triangle 
20090203 

Inez pose la question : If you have a 306090 triangle and the only side you get is 73 and a 90 degree box, how do you find the area? Penny Nom lui répond. 





Calculating markup 
20090203 

Tonya pose la question : I'm trying to figure out the formula for the following, I have a product that I want to receive a certain profit, but with this product I also have to pay a percentage of commission to someone. I need to know how to calculate my new selling price taking into account the markup percentage, but I don't want my cut to be lowered. I have calculated the markup percentage to get my new selling price with the commission, but it lowers my cut once I pay the commission and I don't want it to do that. Thanks Penny Nom lui répond. 





Simultaneous equations with an xy term 
20090201 

angelee pose la question : xy+5x2y10=0
2x+y=1 Penny Nom lui répond. 





limit sinx/x 
20090130 

Jackie pose la question : how to evaluate limit sinx/x as x tends to zero if x is in degrees Stephen La Rocque and Harley Weston lui répond. 





25,000 pounds of sheet metal 
20090127 

JESSICA pose la question : I need to convert 25,000 lbs. of 32x48 sheet metal into total sq. feet. What would be my formula? Robert Dawson lui répond. 





The dimensions of a pool 
20090118 

denise pose la question : a rectangular swimming pool is three times as long as it is wide. if the perimeter of the pool is 320 feet, what are its dimensions Penny Nom lui répond. 





The whole number that precedes a number w+3 
20090117 

Morgan pose la question : write a variable expression for
"The whole number that precedes a number w+3" Penny Nom lui répond. 





Fuel in a tank 
20090116 

Steve pose la question : I am not a math expert and want help seeing how much fuel is in a tank at one given time the tank that i have is 27 inches round. It is 69 inches long. laying length ways. it holds 140 gallons of fuel at fill up. I do know that it would hold less at the bottom of the tank an more in the center. Is there anybody that could just give me the figures by the inch without a formula. thanks for your time Stephen La Rocque lui répond. 





0.0708 lbs per linear yard 
20090116 

Kevin pose la question : If I know that my product is .0708lbs per linear yard how do I calculate how many Linear yards are in a lb? Penny Nom lui répond. 





An expression for q quarters and n nickles 
20090116 

Morgan pose la question : a variable expression for:
"The value in cents of q quarters and n nickels" Penny Nom lui répond. 





Does probability apply here? 
20090115 

Paul pose la question : Suppose I have a dice in my hand that I am about to roll. The probability that I roll a six is, all things being equal, 1/6. I accept that.
Suppose now the I roll the dice and immediately cup my hand over the result. What is the probability that I have rolled a six? People seem to want to say it is still 1/6. But it can't be can it!? It is surely either 1 or 0, depending on whether I have in fact rolled a six? Robert Dawson lui répond. 





A one cubic mile lake 
20090109 

dye pose la question : how many liters are in a one cubic mile lake Robert Dawson lui répond. 





660 yards = ?? miles 
20090108 

Ashley pose la question : How do I convert yards to miles, specifically, 660 yards = x miles. Please show work so I can figure other problems out. Penny Nom lui répond. 





(a x b) intersect (b x a) 
20090108 

sean pose la question : is it possible to have two sets such that
n((a X b) intersect (b X a) =3 Harley Weston lui répond. 





Numbers or Percentage or probability or what? 
20090107 

Chew pose la question : Teacher A teaches 50 students and 45 of them obtained straight As.
Teacher B teaches 5 students and 5 of them obtained straight As.
Which teacher would you send you child to and why? Robert Dawson and Harley Weston lui répond. 





Converting grams to milliliters 
20090104 

Faiza pose la question : I was looking for how to convert grams into mL and I read on this site
to convert one to the other you need to know what substance you are measuring.
so if I am measuring sugar or any of the baking ingredient like flour how do
I convert them from grams to mL is there a simple method I can use to do that? Penny Nom lui répond. 





The square root of 164 
20081231 

Melissa pose la question : How do you simplify the square root of 164? Stephen La Rocque lui répond. 





The volume of a feed hopper 
20081218 

John pose la question : I need to calculate the volume of a feed hopper, and I'm not sure how to break it down. The top of the hopper is 36" x 36", it is 30" deep, and ends at a 6" x 6" plate. One side of the hopper is straight top to bottom, of course tapering on two sides to meet at the plate. The other three sides angle down at about 75 degrees. I need to determine the cubic foot volume of this hopper (it is used for ground coffee) so I can configure a vibrator to knock down residual grounds. Thanks. Robert Dawson lui répond. 





The angle between two lines 
20081217 

abhi pose la question : how to calculate the angle between two lines, given the length of the lines..
angle should vary from 0  360 in the counterclockwise direction Robert Dawson and Harley Weston lui répond. 





650g+2kg+195g=how many kg 
20081211 

christian pose la question : 650g+2kg+195g=how many kg Penny lui répond. 





Wall covering 
20081210 

Jeanie pose la question : I need to convert 14 LY of wallcovering (54" wide) to square feet. Can you please help me? Penny Nom lui répond. 





The volume of a pipe 
20081210 

Walter pose la question : What is the volume of a pipe 7.92 inches inside diameter and 22 km. long in cubic feet of water Robert Dawson and Harley Weston lui répond. 





A wine decanter 
20081210 

Suzanne pose la question : I am trying to buy a wine decanter for my dad for Christmas. One big
problem I am having shopping online is finding the right size. Wine is sold
by metric ml, with a standard bottle holding 750ml of wine. Decanters are
measured by oz, and the sizes are all over the place, with one site alone
having sizes 25oz, 26 1/2oz, 50oz, 59 1/8oz, and 68oz.
Can you help me with metric conversions so I can figure out how much wine
these decanters hold? Like everybody else, I need this as soon as possible
so I can get it shipped in time for Christmas. (I'm disabled & don't drive, so
online shopping is my only way to get gifts.)
Thanks for your help!
Suzanne Chris Fisher and Robert Dawson lui répond. 





What is one trillion divided by 10? 
20081209 

mark pose la question : can you please tell me what one trillion divided by 10 is Robert Dawson and Penny Nom lui répond. 





The volume of a yogurt pot 
20081204 

Robyn pose la question : Okay, I know you have some answers on converting this already, but I can not convert the yoghurt pot I need yet into ml.
Is there some way to explain this using the yoghurt as an example?
The pot's 150g of lowfat strawberry yoghurt... would the 'lowfat' have an effect on this?
I'm sorry if this is a bother for you to answer, I just don't seem to be able to get it...
Have a nice day.
 Robyn Janice Cotcher and Penny Nom lui répond. 





Division in different bases 
20081202 

MICHELLE pose la question : DIVIDE 538 BY 14 IN BASE 2, 3, 4 & 5 Penny lui répond. 





3 equidistant points 
20081201 

Damien pose la question : How do you find 3 equidistant points (C,D,E) on a line between point A(Xa, Ya) and point B(Xb, Yb) so that AC, CD, DE and EB are all equal? Chris Fisher lui répond. 





What is so important about quadratics? 
20081129 

zoe pose la question : what is so important about quadratics? Harley Weston lui répond. 





Dividing Large Numbers 
20081126 

Mark pose la question : what is 7.9 trillion divided by 301 million? Janice Cotcher lui répond. 





The path of a small sailboat 
20081119 

jane pose la question : a sailor in a small sailboat encounters shifting winds. she sails 2.00 km East
then 3.40 km North East, then an additional distance in an unknown direction. Her final position
is 6.68 km directly east of the starting point. find the magnitude & direction
of the third leg of the voyage. Harley Weston lui répond. 





An algebraic exercise with fractions and radicals 
20081118 

Rubén pose la question : Question from Rubén, a teacher:
I have the ecuation:
U = [yb / (ab+a^2)]^1/2 + [ya / (ab+b^2)]^1/2
I know for sure this reduces to
U = [y (1/a + 1/b)]^1/2
but I cannot find a way to get into that result!
Thanks Rubén Osuna lui répond. 





The midpoint o a line segment 
20081115 

Jane pose la question : The vertices of a triangle are at (1,7), (6,1) and (0,3). Find the coordinates of the midpoints of the sides. Penny Nom lui répond. 





A ratio to a decimal 
20081114 

manny pose la question : Express 22 : 5 as a decimal. Round to the nearest hundredth Penny Nom lui répond. 





How far are the boats apart? 
20081114 

dom pose la question : Two boats leave port at the same time. They leave at 150 degree angle. One boat travels at 10mph and the other at 20mph. After two hours how far are the boats apart? Penny Nom lui répond. 





The angles and sides of a triangle 
20081113 

JAMIE pose la question : a triangle with a side(b)37m an angle(C)70degrees and (a)79m find values of angles A and B and length of side c Stephen La Rocque lui répond. 





An odd shaped lot 
20081113 

Janice pose la question : Hi I am attaching a survey of an odd shaped real estate lot. I am hoping
you can help me determine the acreage.
Janice Harley Weston lui répond. 





How do you work out 2/17 as a decimal? 
20081113 

p pose la question : how do you work out 2/17 as a decimal? Penny Nom lui répond. 





A barrel on its side 
20081113 

Dave pose la question : Question from Dave:
How many gallons are left in a 36x60 in. barrel (laying on its side) and has 16 in. of gasoline left. I have attached a diagram. Harley Weston lui répond. 





Math and nursing 
20081110 

alina pose la question : how many math do you net for nurse Stephen La Rocque lui répond. 





A flagpole and a yardstick 
20081107 

Wanda pose la question : One boy holds a yardstick vertically at a point 40 feet from the base of the flagpole. The other boy backs away from the pole to a point where he sights the top of the pole over the top of the yardstick. If his position is 1 ft 9 in from the yardstick and his eye level is 2 ft above the ground, find the height of the flagpole. Penny Nom lui répond. 





A bay window 
20081030 

Scott pose la question : Given the length of an arc, the rise of an arc, and the number of segments
that I need to divide the arc into  how do I determine the length of each
segment? Imagine a bay window. It could have 5 side or 7 sides, just as
an example. How do I determine the width of each window given that the
unit will be mounted into a frame with a 96 inch opening. The rise of the
unit will extend out 18 inches. Lets say that the number of single windows
unit within the unit is 5. How wide should each window be? Do you
understand? Harley Weston lui répond. 





The length of a rectangle is 6 inches less than 3 times its width. 
20081026 

Angela pose la question : The length of a rectangle is 6 inches less than 3 times its width. Find the
dimensions of the rectangle if its area is 45 square inches. Penny Nom lui répond. 





Put in lowest terms 6a^2c/8ab 
20081024 

hana pose la question : put in lowest terms 6a^2c/8ab Stephen La Rocque lui répond. 





A falling block 
20081018 

KOBINA pose la question : A 50 kg block being held at rest 20m above the ground is released. the block falls (no friction). how fast is the block traveling (in m/sec) when it has lost 40% of its original potential energy. Stephen La Rocque lui répond. 





Two equations in two unknowns 
20081017 

Dushayne pose la question : Please help me in solving this problem:
a. 3x4y=32
5x+2y=10
b. 2x+3y=11
4x+3y=10 Penny Nom lui répond. 





The dimensions of a rectangle 
20081016 

cristine pose la question : the area of a rectangle is 675sq.cm.
if the width is 1/3 of the length.
find the dimensions of the rectangle.... Penny Nom lui répond. 





Millimeters to inches 
20081015 

diane pose la question : can you convert milliliters to inches? Penny Nom lui répond. 





The sides of an octagon 
20081012 

side lengthsGarry pose la question : I need the length of the sides and the degrees of the angles for a 30 inch diameter
octagon Janice Cotcher lui répond. 





The dimensions of a pool 
20081008 

Justine pose la question : This may be a really silly question but I am trying to work out what the possible dimension a pool may be if we have 20m length of wall of an above ground pool (laid out flat on ground)
We have been given a second hand above ground pool and we know it was in an oval configuration and we are just trying to get a guesstimate of the potential size it may be as the people couldn't tell us the size Penny Nom lui répond. 





Algebraic fractions 
20081006 

Kayla pose la question : (x^29)/x times (x^34x)/(x^2+5x+6) Harley Weston lui répond. 





A product of positive and negative numbers 
20081003 

kaylou pose la question : Suppose you were given 13 numbers and asked to find their product.
Seven of the numbers were positive, and the rest were negative.
Would your product be positive or negative? Why? Penny Nom lui répond. 





The unusable space in a container 
20081002 

Billy pose la question : an object is 42 inches long, 29 inches wide, and 69 inches high. The usable capacity of this container is 36.4 cubic feet. How much space in percentage is left over from the container? Penny Nom lui répond. 





Does an oval have sides? 
20081002 

reid pose la question : My 6 yo neice came home with her math homework and she was supposed to identify which objects had sides.One of the objects was an oval.I don't believe it has sides because it is curved and I don't think that would make it an object with sides.What would be the correct answer?Thanks,Reid Janice Cotcher lui répond. 





The length of a tank 
20081001 

alex pose la question : I have a tank which I can only partly see. It is 70cms wide, 45 cm deep and hold 500litres. How long is it? Harley Weston lui répond. 





Conversion to cubic feet 
20081001 

Dorothy pose la question : What is the cubic feet of an item that is 7"x16 7/8"x19" Harley Weston lui répond. 





z(z+1)x(x+1) / zx 
20080930 

sylvia pose la question : z(z+1)x(x+1) / zx
HOW DO I SIMPLIFY THIS Penny Nom lui répond. 





3,6,10,15,and 21 
20080928 

jarred pose la question : i am currently stumped on a math project that requires me to find out the recursive formula for a sequence of numbers. the numbers in the sequence are 3,6,10,15,and 21. Thank you for your time. Walter Whiteley lui répond. 





144 square inches 
20080927 

mike pose la question : how much cm is in 144 square inches? Penny Nom lui répond. 





Simplify 6(a+2b)+8a16b 
20080927 

madison pose la question : 6(a+2b)+8a16b Penny Nom lui répond. 





Three equal ratios 
20080926 

Jodi pose la question : For the ratio given, find three equal ratios: 2 miles/8 minutes Penny Nom lui répond. 





Sample variance: inches to centimeters 
20080922 

Anita pose la question : The average height of a sample of basketball players is 6 feet, 2 inches or 74 inches.
The standard deviation of this sample of players is 4 inches. If each person's height were to be multiplied by 2.54, what would be the value of the resulting sample variance? Harley Weston lui répond. 





The sides of an octagon 
20080921 

mark pose la question : I need to know the measurements of an octagon with a inside diameter of 34.5 inches from side to side Penny Nom lui répond. 





Simplify [[1/(x+3)]1/3]/x 
20080919 

diana pose la question : How does [[1/(x+3)]1/3]/x simplify Harley Weston lui répond. 





Oils and fats 
20080918 

Barry pose la question : I'm doing a nutrition assignment and I'm adding up my Oils and Fats category.
I have 10ml of butter to add to 31g of fat so I'm trying to figure out what to do or I should say how to figure out the answer.
Barry Penny Nom lui répond. 





The weight of a concrete cylinder 
20080918 

Curtis pose la question : I am trying to calculate the weight of a concrete cylinder. The diameter is 56" and the thickness or depth is 24". Can anyone help me? If possible I would like to see the formula as to how the answer was derived. Thank you Harley Weston lui répond. 





Simplifying equations 
20080918 

diana pose la question : I do not know how to simplify equations. How does 5x^27X+2 become (x1) (5x2)? Penny Nom lui répond. 





Cubic yards and quarts 
20080916 

Mary pose la question : I need 2 yards of soil, how many quarts is this? Penny Nom lui répond. 





Three addends that sum to ten 
20080913 

Alfred pose la question : How many probabilities are there to have 3 addends to get a sum of 10? What is the formula? Harley Weston lui répond. 





A number that divides by six but not by three 
20080912 

Ken pose la question : A number that divides by six but not by three Stephen La Rocque and Victoria West lui répond. 





How would put .12 with 2 repeating into a fraction? 
20080909 

Savanna pose la question : How would put .12 with 2 repeating in fraction?
Savanna! Penny Nom lui répond. 





How many ml are in 40 grams? 
20080909 

Nancy pose la question : I need to know how many ml are in 40 grams. So what is the base 1ml= how may grams Harley Weston lui répond. 





An exclusion zone around a triangle 
20080907 

Awrongo pose la question : A long time ago Mr Gibson found an island shaped as a triangle with three straight shores of length 3 km,4 km and 5 km. He declared an 'exclusion zone' around his island and forbade anyone to come within 1 km of his shore. What was the area of his exclusion zone? Stephen La Rocque and Penny Nom lui répond. 





A security camera 
20080907 

Rita pose la question : A security camera in a neighborhhod carnival is mounted on a wall 9 feet above the floor inside a video gallery. What angle of depression should be used if the camera is to be directed to a spot 6 feet above the floor and 12 feet from the wall? Stephen La Rocque and Harley Weston lui répond. 





Simplify ((5/7)/(5/14)) + (3/4) 
20080906 

Emal pose la question : How do you simplify completely: ((5/7)/(5/14)) + (3/4)? Penny Nom lui répond. 





3 miles in 6 seconds 
20080905 

Grant pose la question : if a rocket sled is traveling 3 miles in 6 seconds, how fast is it going in miles per hour? Harley Weston lui répond. 





The selling price 
20080904 

Robert pose la question : Client wants to sell his property providing he is left with 100000.00$ net.
How do I calculate selling price if commission is 6% and taxes on the commission 6% Fed and 7.5%prov.
I'm taking the real estate class and this one really got me. Penny Nom lui répond. 





I need an equation that best fits these numbers. 
20080903 

Vallatini, pose la question : Attached, please find a plotted curve (pdf file). I have pulled values from this curve (see below). I need an equation that best fits these numbers. Can you help? Harley Weston lui répond. 





An algebraic expression 
20080829 

Antonio pose la question : write a variable expression for 9 less than k Penny Nom lui répond. 





Long Division with Decimals 
20080828 

Ghita pose la question : I need help with these 2 questions:
Find the quotients:
52.576 divided by 21
71.331 divided by 93
Ralph spent 5/9 of an hour mixing paints and 7/9 of an hour painting.How much time in all did Ralph spend on his project?
Thank you,Please answer soon Janice Cotcher lui répond. 





557 mL of benzaldehyde 
20080828 

Kara pose la question : Calculate the mass of 557 mL of benzaldehyde. The density of benzaldehyde is 1.04 g/mL. Penny Nom lui répond. 





The square root of a fraction 
20080824 

Lauren pose la question : How do you solve square roots of fractions? Does the format change if it is either a proper or an improper fraction?
Ex. the square root of 1/4 or the square roots of 80/25 Penny Nom lui répond. 





Radii and Chords Create a NonRight Triangle 
20080822 

Beary pose la question : AOC is a diameter of circle O. Line AB is 12, and lines OA and OC (the radii) are 10. Find the length of line BO and chord BC. Janice Cotcher lui répond. 





Simplifying Algebraic Expressions 
20080822 

Jacky pose la question : x^2y^2+4x+4y Penny Nom lui répond. 





Converting centimetres to metres 
20080821 

walter pose la question : how do you convert the smaller unit to a decimal of the larger unit and then solve
17 m  130 cm Penny Nom lui répond. 





Angular & Linear Speed from a Sine Graph 
20080819 

Kim pose la question : Kim, a student:
I am given a graph with a wave. The amplitude is 5cm and the period is 4cm. I am suppose to find the angular speed. What I need to know is the formula for angular speed and how do I use these numbers to get the correct answer. Janice Cotcher lui répond. 





Metres and miles 
20080818 

Bill pose la question : I enter a race that is 10,000 meters long,how many miles do i have to run? Victoria West lui répond. 





Solving for Shared Height of Two Right Triangles 
20080817 

Heidi pose la question : find the height of a triangle, which can be split into two right triangles, but the base (50m) is not split equally in half. one end of the base is 40 degrees, while the other is 30 degrees. Janice Cotcher lui répond. 





Similar Triangles Given a Median 
20080817 

RAM pose la question : Sides AB , AC and median AD of a triangle ABC are respectively proportional to
PQ PR and median PM of another triangle PQR. Show that ABC is similar to PQR Janice Cotcher lui répond. 





Converting to cubic yards 
20080815 

Lisa pose la question : I need to convert 32,000 square feet, 5 inches deep to cubic yards. Can you help me?
Thank you Harley Weston lui répond. 





Similar triangles 
20080812 

ramarao pose la question : D is a point on side BC of a triangle ABC such that BD/CD=AB/AC. prove that AD is the bisector
AD is the bisector of BAC Chris Fisher lui répond. 





Arclength and sectorangle 
20080806 

Benson pose la question : If chord length, radius are given, How to find the sector angle and arclength Janice Cotcher lui répond. 





24 in by 14 in by 14 in in cubic feet 
20080805 

Tom pose la question : I have a box that has internal dimensions of: 24in. H x 14in. W x 14in. D.
How many cubic feet is this internal space? Penny Nom and Victoria West lui répond. 





Why can't you divide by zero? 
20080804 

Donna pose la question : Why can't you divide by zero? Chris Fisher lui répond. 





Lot size of a four sided lot 
20080730 

JAMES pose la question : I'm trying to find out this lot
size in acres.
I looked at a bunch of your suggestions, but I guess
I'm not smart enough
to figure it out.. I have attached an image of the
lot, hopefully with
enough info. for you..
Thanks,
Jim Penny Nom lui répond. 





Right Sided Limit of an Exponential Function 
20080729 

joseph pose la question : I am trying to find the limit as X approaches 0 from the positive side of x to the sin of x
which look like this lim x^sinx
x>0+ Harley Weston lui répond. 





Trigonometric 
20080728 

kiran pose la question : In triangle , Sin@ = ? Penny Nom lui répond. 





What is the domain of (f/g)x? 
20080728 

Warren pose la question : If f(x)=3x5 and g(x) = square root of x5, what is the domain of (f/g)x? Penny Nom lui répond. 





Alpha level 
20080723 

anonymous pose la question : What is the advantage of using an alpha level of .01 versus a level of .05, What is the disadvantage of using a smaller alpha level? Janice Cotcher lui répond. 





Simultaneous equations 
20080723 

Franco pose la question : Solve
3 D + E  F = 10
2 D  F = 4
3 D  4 E  F = 25
Franco Penny Nom lui répond. 





Choosing 4 numbers from 70 numbers 
20080721 

Jeannine pose la question : When using numbers from 1 to 70 in sets of 4, how many combinations are there without having the same combination twice?
Thanks Penny Nom lui répond. 





Three consecutive positive integers 
20080720 

AC pose la question : find three consecutive positive integers such that the product of the first and third, minus the second, is 1 more than 4 times the third Penny Nom lui répond. 





A bijection from (0,1)x(0,1) to (0,1) 
20080720 

Adam pose la question : I'm trying to prove that the function that takes the open square (0,1)x(0,1) to (0,1) is a bijection (and hence a continuum).
If we take an element (x,y) of (0,1)x(0,1) and represent (x,y) as (0.x1 x2 x3 x4..., 0.y1 y2 y3 y4...) aka x1 represents the tenths digit of x, x2 represents the hundredths, etc. Then we can define a function
f((x,y)) = 0.x1 y1 x2 y2 x3 y3... However, this is not a bijection. I hypothesize this is because you'd be unable to create the number 0.1 as x=0.1 and would have to be y=0, which contradicts the open interval (0,1) defined for y. We have been told though, if we create the same function, except that we "group" 9's with their next digit into a "block"
we can create a bijection. For example, if x=0.786923 and y=0.699213, then we define x1 to x3 as normal, but x4= 92, and x5=3. For y, we define y1 as normal, but y2=992, and y3 to y4 as normal. hence f((x,y)) = 0.7 6 8 992 6 1 92 3 3.
My questions are a) is my hypothesis on why the original function is not a bijection correct? b) why does the special blocking in the new function make a bijection? Victoria West lui répond. 





A silo with a flat side 
20080714 

Amy pose la question : Without using the Pythagorean Theorem, determine the capacity of a silo in cubic feet of grain if: the cylindershaped silo has one flat, rectangular face that rests against the side of the barn; the height of the silo is 30 feet and the face resting against the barn is 10 feet wide; the barn is approximately 5 feet from the center of the silo. Harley Weston lui répond. 





A four sided lot 
20080709 

michelle pose la question : the front is 65.29
left side 162.26
the back 155.00
right side 101.01
right angle=50.00
left angle= 153.30 Harley Weston lui répond. 





Neither prime nor composite 
20080708 

saloni pose la question : Give the counting number which is neither prime nor composite ? Penny Nom lui répond. 





Divisibility by 11 
20080704 

Peter pose la question : For what single digit value of n is the number n53nn672 divisible by 11? Leeanne Boehm lui répond. 





Composition of two functions 
20080704 

Kristian pose la question : f(x)= the square of x add to 1 and g(x)=1/x
find: (f o g)x Penny Nom lui répond. 





Polynomial division and remainders 
20080702 

RAM pose la question : If the polynomial x46x3+16x225x+10 is divided by another polynomial x22x+k, the remainder
comes out to be x+a. Find k and a. Janet Cotcher and Harley Weston lui répond. 





Kilometers per liters to miles per gallon 
20080626 

margaret pose la question : we travelled 130 kilometers on 10 liters of gas. How many miles to the gallon did I get Penny Nom lui répond. 





The smallest number divisible by 1 to 9 
20080626 

Peggy pose la question : What is the smallest number divisible by each of the first nine counting numbers? Penny Nom lui répond. 





A six sided lot 
20080625 

Zack pose la question : Please help me find the area of my lot. I am sending a fax of the drawing and dimensions.
Zack Harley Weston lui répond. 





How many pounds in 300 grams? 
20080624 

Renelda pose la question : How many pounds in 300 grams? Can you send the formula? Thanks Penny Nom lui répond. 





The sum of the digits of a number 
20080623 

Ben pose la question : Question: Using mathematical induction, prove that if the sum of the digits of a number is divisible by three, then the number itself is also divisible by 3. Penny Nom lui répond. 





9(d+5)=3(d3)+6d 
20080619 

davontay pose la question : 9(d+5)=3(d3)+6d Harley Weston lui répond. 





Concrete blocks 
20080618 

marvin pose la question : How many cement blocks do i need to build a 8 ft. tall wall x 1,300 ft. long? Harley Weston lui répond. 





How do you change bases? 
20080617 

Peter pose la question : How do you change bases eg. 121 from base 3 to base 5? Penny Nom lui répond. 





2(x  1)^2 + 8 
20080612 

kasondra pose la question : y=2(x1)2[thats a square] +8 that need to be put in standard form
the answer is y= 2x2 4x + 6
i got y= 2x2 4x 4
i just don't get how my teacher got that answer Penny Nom lui répond. 





The weight of concrete 
20080611 

Daniel pose la question : I need to calculate the weight of Concrete in a slab that measures 2' x 4' x 4" thick.
I am pricing out a job and have two different size stones to work with, the second stone measures
2' x 2' x 4". Harley Weston lui répond. 





What are the dimensions of the rectangle? 
20080611 

Denise pose la question : A rectangle has a diagonal that is 3.6 feet longer than the length and 7.1 feet longer than the width. What are the dimensions of the rectangle? Claude Tardif and Victoria West lui répond. 





A recursive formula for 9, 18, 36, 27, ... 
20080605 

Rita pose la question : I am having trouble understanding how to write formulas (I should say create formulas) from a given sequence.
It does not matter what sort of sequence it is. The confusion remains.
I have not found a textbook or easy math book that explains this process for the average Joe to grasp.
Here are the two questions:
(1) Write a recursive formula for the sequence
9, 18, 36, 72, ...
(2) Write a recursive formula for the sequence
3, 3(sqrt{3}), 9, 9(sqrt{3}) Penny Nom lui répond. 





A 4 sided lot 
20080603 

Pat pose la question : If a lot of property is: front 127.87, back 156.17, one side
is
129.73, the other side is 125.00, then how much total acreage is
this. Harley Weston lui répond. 





The area of a regular pentagon 
20080602 

Jenna pose la question : I would like to know if there is a formula to find the area of a regular Pentagon that is not inscribed in a circle only apothem and side length are given. Penny Nom lui répond. 





4x^3  6x + 2 = 0 
20080528 

paul pose la question : 4x^3  6x + 2 = 0 Janice Cotcher lui répond. 





Convert cubic inches to gallons 
20080526 

Rosemarie pose la question : How do you convert cubic inches to gallons? Thanks for your help. Penny Nom lui répond. 





.5 cu ft of sand to lbs. 
20080525 

rogersimmons pose la question : needtocovert .5 cu ft. of sand into lbs. Penny Nom lui répond. 





3 radical 48 +11 radical 75 
20080524 

Maria pose la question : Add 3 radical 48 +11 radical 75. Write answer in simpliest form. Penny Nom lui répond. 





Double the the dimensions of a rectangle 
20080522 

Destiny pose la question : Double the the dimensions of a rectangle that is 3 by 4 in. What is the area? Penny Nom lui répond. 





Volume/weight of a salt shedweight 
20080521 

James pose la question : How do I find the volume/weight of a salt shed. I have a 3000 ton barn, I need a better way of finding how much salt to order as it gets used. I know how to calculate volume, how do i get tonnage from there?? Harley Weston lui répond. 





Nine digit numbers 
20080521 

Alex pose la question : List of Nine digit numbers, that can be divided by nine? Janice Cotcher lui répond. 





1+1/1+1/x 
20080521 

nadean pose la question : 1+1/1+1/x Penny Nom lui répond. 





A weird shaped lot 
20080521 

James pose la question : Need to find square foot of a residential lot on a culdesac. Weird triangular shape. Measurements : 126.18 170.08 138.2 48.4 Harley Weston lui répond. 





Converting a decimal to a fraction 
20080519 

judy pose la question : please explain how to get from the decimal number .3437 to the fraction 11/32 Leeanne Boehm lui répond. 





Guy wires for a tower 
20080519 

larissa pose la question : a radio tower 500 feet high is located on the side of a hill ( the hill has an inclination to the horizontal of 5 degrees.) How long should two guy wires be if they are connected to the top of the tower and are secured at two points 100 feet directly above ( up the hill ) and directly below the base of the tower? Penny Nom lui répond. 





Fencing around a playground 
20080515 

Vanessa pose la question : If the playground is a rectangle with it's width 10ft shorter than it's length,
and it can be enclosed by exactly 140ft of fence,
what is the length and width of the playground? Penny Nom lui répond. 





The fourth side of a property 
20080514 

Penny pose la question : Property has 3 measurements and 2 angles and I want the altitude at a particular point. Corners are sw, nw, ne and se. 1 want the 4th saide measurement confirmed (we think 146.07') and the altitude measurement at 25' from sw (on the swse side)
The angles provided are interior at nw 67.38 degrees and the opposing corner se interior appears to be 68.58 degrees. the 3 sides with measurements are: sw to nw=54.07'. sw to se 146.07' and se to ne 53.57'. If you would help, we would really appreciate it. Thanks! Penny Harley Weston lui répond. 





How much seed do I need per plot? 
20080513 

Jaye pose la question : The plot size is 5 m X 2 m. The seeding rate is 12Kg/ha. How much seed do I need per plot? I have failed to get a proper answer.
Thank you. Penny Nom lui répond. 





The weight of a concrete column 
20080511 

russell pose la question : a cylindrical form is filled with a slow curing concrete. The base of the form
is 10 ft in radius, and height is 25 ft. while the concrete hardens, gravity
causes the density to vary from a density of 90 lbs/ft^3 at the bottom to a
density of 50 lb/ft^3 at the top. Assume that the density varies linearly
from the top to the bottom, and compute the total weight of the resulting
concrete column Harley Weston lui répond. 





Selling price 
20080510 

Roxane pose la question : I'm trying to figure out the formula for the following, I have a product that
I want to receive a certain profit margin, but with this product I also have
to pay a percentage of commission to someone. I need to know how to
calculate my new selling price taking into account the markup percentage, but
I don't want my gross margin to be lowered. I have calculated the markup
percentage to get my new selling price with the commission, but it lowers
my profit margin once I pay the commission and I don't want it to do that. Penny Nom lui répond. 





The sides of an octagon 
20080507 

Frank pose la question : Question from Frank, a parent:
Hi,
Need to lay out a 10 ft. diameter octagon on the ground. What is the
length of the
sides ? And the angles ? Harley Weston lui répond. 





Four cookies 
20080503 

tashera pose la question : if a serving is 5 cookies. how many servings can i make from 4 cookies? Stephen La Rocque lui répond. 





How many gallons are in 1,500 liters? 
20080501 

bambi pose la question : [How many gallons are in 1,500 liters? Penny Nom lui répond. 





Division by zero 
20080501 

Bill pose la question : Why does multiplication have a favored status so as to make division by zero undefined? Harley Weston lui répond. 





1/35/6=1/x, solve for x 
20080501 

Lavada pose la question : 1/35/6=1/x How do I solve this problem. Penny Nom lui répond. 





(9x^24)/(3x^25x+2) * (9x^4  6x^3 +4x^2)/(27x^4+8x) 
20080429 

Jonathon pose la question : I don't remember how to solve an equation in the form of the following:
(9x^24)/(3x^25x+2) * (9x^4  6x^3 +4x^2)/(27x^4+8x) = Stephen La Rocque lui répond. 





Converting metric density 
20080428 

Hilary pose la question : 10g/100ml=?g/?l
52g/100ml=?g/?l
65g/100ml=?g/?l
100g/100ml=?g/?l
137g/100ml=?g/?l
0.15g/100ml=?g/?l Penny Nom lui répond. 





WHY 144 where does this figure come from 
20080419 

Sean pose la question : Why do you use the number 144 to divide
EG. length of timber 2 inches x 8 inches x 14 foot = 1.5 cubic feet
Calculation is 2x8x14 =224 divide by 144 = 1.5 WHY 144 where does this figure come from Leeanne Boehm lui répond. 





Simplify 5x^5/8 / 15x^2/12 
20080418 

Kyler pose la question : 5x^5/8 / 15x^2/12 Divide the rational expressions. Simplify the results. Penny Nom lui répond. 





The three sides of a triangle 
20080416 

Bridgett pose la question : The sum of the lengths of any 2 sides of a triangle must be greater than the third side. If the triangle has one side that is 11 CM, and the second side of the triangle is 4 cm less than twice the third side, what lengths do the 2nd and 3rd side have to be?
between 00000000 and 99999999 Stephen La Rocque lui répond. 





What is 300% as a fraction? 
20080414 

Carli pose la question : what is 300% as a fraction Stephen La Rocque lui répond. 





A 13 cubic foot cylinder filled with sand 
20080412 

Thomas pose la question : I have a 100 pound bag of sand. I need to know how much sand I will need to fill a 13 cubic foot cylinder Harley Weston lui répond. 





The capacity of a silo 
20080412 

Candonn pose la question : I have a cement silo that is 30 ft. high and has a diameter of 12 ft.
I was wondering what the capacity of the silo is in tons of dry material.
The silo is flat on the bottom also. Penny Nom lui répond. 





Some 4 sided polygons 
20080411 

kathy pose la question : I am a 4th grade student and need to complete this question:
I need to draw 2 polygons with 4 sides and 2 right angles. Please help. Thanks Penny Nom lui répond. 





Side lengths and angles in a regular octagon 
20080409 

Lori pose la question : I am a builder and need to find the length of the sides of an octagon. I know the length between
the parallel sides (26 feet). What is the length of each side? What is the angle measurement? Harley Weston lui répond. 





The weight of 1 litre of milk 
20080407 

IMRAN pose la question : WHAT WEIGHT IN KILOGRAMS DOES 1 LITRE OF MILK HAVE? Penny Nom lui répond. 





Composition of functions: feet, inches and yards 
20080405 

Coya pose la question : write a function f(x) that converts feet to inches.Now write a function g(x) that converts yards to feet. Explain what the composite function f(g(x)) means. Then evaluate f(g(x)) for x = 3,6, and 9. Stephen La Rocque lui répond. 





Compatible numbers 
20080404 

dawn pose la question : Need help. Estimate the quotient. Tell what compatible numbers you used.
817divided by 4 = Penny Nom lui répond. 





100 yards of cloth 
20080404 

Leroy pose la question : (100 yards of cloth 48 inches = how many square yards) Penny Nom lui répond. 





Ounces and grams 
20080402 

Rakesh pose la question : 7.2 oz per sq. yard equals ? __ grams per sq. meter
How I can measure the weight of a Jeans fabric (in oz)? And what is the rellation between grams and oz? Penny Nom lui répond. 





Common fraction to decimal fraction 
20080401 

chadwick pose la question : how do I turn 3/32 into a decimal Penny Nom lui répond. 





2 ^ 2 + (6  9) / (3) + 4 * (2) 
20080401 

Jeth pose la question : How do I simplify: 2 ^ 2 + (6  9) / (3) + 4 * (2) Penny Nom lui répond. 





Square feet and square yards 
20080401 

Victor pose la question : 6200 sq. ft.into yards Penny Nom lui répond. 





A car tire full of concrete 
20080327 

robert pose la question : I want to build a volleyball net support. I am using a car tire 24"odx16"id filled with concrete. how much will this weigh? thanks Penny Nom lui répond. 





Similar triangles 
20080326 

Nisha pose la question : In triangle ABC, LM is parallel to AB. If AL=x3,AC=2x,BM=x2,BC=2x=3. Find x Penny Nom lui répond. 





Light years to miles 
20080324 

Robert pose la question : HOW MANY MILES ARE THERE IN 7.5 BILLION LIGHT YEARS. Penny Nom lui répond. 





Converting ounces to milliliters 
20080321 

kelly pose la question : As I have to drink 12  8 ounce glasses of water a day and my water bottle holds 591 ml, how many bottles of water must I drink? Penny Nom lui répond. 





How would I graph: x  2 divided by x^2  4? 
20080319 

Sean pose la question : How would I graph: x  2 divided by x^2  4 using a method in extreme values of
functions or completing the square
x  2/ x^24 Stephen La Rocque lui répond. 





Determine the capacity of Farmer John's silo 
20080316 

paula pose la question : Farmer John stores grain in a large silo located at the edge of his farm. The cylindershaped silo has one flat, rectangular face that rests against the side of his barn. The height of the silo is 30 feet and the face resting against the barn is 10 feet wide. If the barn is approximately 5 feet from the center of the silo, determine the capacity of Farmer John’s silo in cubic feet of grain. Penny Nom lui répond. 





The limit of (sin4x)/(tan9x) as x approaches zero 
20080314 

stev pose la question : as x>0. How do you find the limit of f(x)=(sin4x)/(tan9X) Harley Weston lui répond. 





The length of a side of a square 
20080312 

laura pose la question : if i had a square of 2.3 square meters what would its radius be?(in centimeters please) Penny Nom lui répond. 





Moving grain across the river 
20080312 

Janice pose la question : Wesley needs to move 820 kg of grain across the river in a canoe that can carry no more than 120 kg. Wesley has a mass of 70 kg. What is the fewest number of trips he will have to make? A. 17 trips; B. 18 trips; C. 32 trips; D. 33 trips. Penny Nom lui répond. 





A ton of carbon dioxide 
20080311 

claire pose la question : I want to know the size of a box if it contained a ton of Co2? Stephen La Rocque lui répond. 





Repeating decimals 
20080310 

Blaine pose la question : Is it possible to put a repeating decimal number into a calculator to solve a problem?
EX: Write 39.3939... as a fraction. Penny Nom lui répond. 





Side lengths and area of a triangle 
20080308 

angela pose la question : In the diagram of ABC the angle A is 65 the angle B is 70 and the side opposite vertex B is 7. Find the length of the side opposite vertex A and find the area of ABC Penny Nom lui répond. 





Composition of functions 
20080307 

sharon pose la question : Find FoG(x)
F(x)= the square root of x9
G(x)= x^2
and also find GoF and their domains Penny Nom lui répond. 





Cubic feet to liters 
20080306 

chase pose la question : if 1cu.ft=6.229 imp. gal and1 imp.gal=4.546 liters how many liters does of 128cuft. hold Penny Nom lui répond. 





The dimensions of a rectangle 
20080306 

Julie pose la question : Find the dimensions of a rectangle with an area of 400. Width x ft.
Length (2x7)ft. Stephen La Rocque and Penny Nom lui répond. 





An arithmetic expression 
20080305 

Kasani pose la question : evaluate the expression: 2^1[14  4(6)]  (7  3) Penny Nom lui répond. 





How large is a container that will hold 3.5 cu meters? 
20080305 

Robert pose la question : If a company allows you to ship personal belongings while on an over seas assignment and the figure is 3.5 cubic meters. Just how much is the total area in square feet?? 10X10X10 or??? I just wanted to understand the size of a container that would hold 3.5 cubic meters!! Harley Weston lui répond. 





What was the ostrich's speed in miles per hour? 
20080303 

jacob pose la question : If it took an ostrich 2.5 seconds to travel 110 feet and the average speed is 44 feet/ seconds, what was the ostrich's speed in miles per hour? Penny Nom lui répond. 





Convert from base 6 to base 12 
20080302 

Jade pose la question : I am trying to convert 13405 base 6 to a base 12 number. I am not allowed to go into a base 10 number. How will can I base 12 without doing anything with base 10? Thank you kindly. Stephen La Rocque and Penny Nom lui répond. 





Simultaneous equations 
20080229 

CONOR pose la question : I was wondering if you could help me with this problem
7x  5y = 1
3y = 4x Penny Nom lui répond. 





150 decimeters is how many centimeters 
20080229 

gayle pose la question : 150 decimeters is how many centimeters Penny Nom lui répond. 





A new carpet 
20080228 

Rhiannon pose la question : The Gatlins are buying a new carpet for their house. They need about
1,175 square feet of carpet. The carpet they buy is sold by the square yard.
Estimate the number of square yards of carpet they need. Do I use the
formula to find the volume or are? Penny Nom lui répond. 





Actural cost, selling price and commission 
20080221 

LiSa pose la question : I have a question about a few things if anyone can answer...
ex.
actual cost (AC) = $1000
selling price (SP) = $
amount earned for company (C) = 15% of... selling price?
commission 1 (C1) = 2.5%
commission 2 (C2) = 2.5%
How would you calculate how much the company's commission amount would be as well as the amounts for the other 2 that get 2.5%? And what would the selling price be? (the 15% $ + 2.5% $ + 2.5% $ ?)
Is the 2.5% taken from the original amount? I am soooo confused!
If anyone could help, that would be great! Harley Weston lui répond. 





Algebraic fractions 
20080221 

sergio pose la question : how to simplify
(x^2 +5x+6)/(x^2  4) x (x^2 5x+6)/(x^29) Stephen La Rocque lui répond. 





8% simple interest for 6 years 
20080220 

Tiffany pose la question : cindy puts 5,025 in a bank account that earns a simple interest rate of 8%. How much money will be in the account at the end of 6 years? Stephen La Rocque and Penny Nom lui répond. 





The length of the third side of a triangle 
20080216 

mary pose la question : I have an angle of 72 degrees and each of the sides are 5' long. What is the distance from each of the ends of the 5 feet to form a triangle. Stephen La Rocque lui répond. 





I am a 4digit number 
20080212 

Nickie pose la question : I am a 4digit number with no repeating digits. I am divisible by 5, my first two digits (left to right) make a number divisible by 3, and my first three digits make a number divisible by 4. Also, my digits have a sum of 19 and I have the digit 7 in the thousands place. Who am I? Penny Nom lui répond. 





Drawing blocks from a box 
20080211 

Inez pose la question : A box contains 3 red blocks and 1 green block. A block is chosen without looking and not put back. Then another block is chosen. What are the possible outcomes? Penny Nom lui répond. 





A flagpole and a statue 
20080209 

Krista pose la question : A flagpole casts a ten meter (m) shadow at the same time as a six metre (m) statute beside it casts a two metre shadow. What is the height of the flagpole?? Steve La Rocque and Penny Nom lui répond. 





A three sided shape 
20080209 

Tim pose la question : Question from Tim:
How would I calculate the area in square feet of a "triangle" with sides:
Base is 36 feet; height is 70 feet; and the thirs side is an arch (curve) of 77 feet. Harley Weston lui répond. 





Why is the number 1 neither prime nor composite? 
20080207 

ronni pose la question : why is the number 1 neither prime nor composite? Harley Weston lui répond. 





Cost per square yard 
20080205 

Terry pose la question : MY cost for seed is $325.00 per acre...i want to bring that down to $ per sqyard. Whats the formula? Penny Nom lui répond. 





The size of a lot 
20080202 

linda pose la question : Hi, could you please tell me how close to an acre of land my lot is. The lot size is 140 ft by 200ft. I am trying to see how close to an acre it is. Penny Nom lui répond. 





The dimensions of a rectangle 
20080201 

Evan pose la question : you are given that the area of a rectangle is 21.6in sq. find the base and the height of the rectangle. Penny Nom lui répond. 





The sign of the quotient of two integers 
20080201 

michelle pose la question : without actually dividing, how can you decide whether the quotient of two integers is A. positive B. negative C. 0? Penny Nom lui répond. 





Bubbles trapped in the volumetric pipet 
20080131 

Nursing pose la question : In determining the density of a liquid, a student left air bubbles trapped in the volumetric pipet. Did this give a density less than expected or greater than expected? Why? Penny Nom lui répond. 





The volume of a tank 
20080127 

Fred pose la question : A cubic tank holds 1,000 kilograms of water what are the dimensions of the tank in meters? Harley Weston lui répond. 





Linear feet to metres 
20080125 

Jillian pose la question : i have a measurement of something in linear feet. i dont know what a linear foot is so i want to convert it to meters to have an idea.
how do i convert. Penny Nom lui répond. 





Converting cubic inches to ounces 
20080122 

kim pose la question : I am trying to find the formula to figure capacity in ounces for the following:
a rectangle 18" long, .75" wide, .75" deep ....
This is for an art project and the cost estimate. Thanks, Kim Penny Nom lui répond. 





How many combinations of 8614 are divisible by 7? 
20080122 

Rebecca pose la question : How many combinations of 8614 are divisible by 7 equally (with no remainder)? Penny Nom lui répond. 





The cosine of an angle 
20080121 

Kristine pose la question : Find measure of unknown side
cosA=0.5 Harley Weston lui répond. 





The angles of a triangle given the three sides 
20080117 

Lucy pose la question : Is there a way to find the angles of a triangle just by knowing the lengths of it's sides?
It seems like the would be a relationship between the two, but I'm not sure. Stephen La Rocque and Harley Weston lui répond. 





Converting mg's to cc's 
20080117 

sandy pose la question : i need to find out how to convert mg's to cc's i need to give 10 mg of liquid and 5 mg of liquid and i only have a dropper that measures cc's please help Stephen La Rocque and Harley Weston lui répond. 





Fact families with multiplication and division 
20080116 

Donna pose la question : I am trying to help my granddaughter with some math homework. I
looked at what you have on fact families. Am I correct to assume that
the same process applies to multiplication and division as well? Her question
asks for fact families for 2, 8, & 16. Penny Nom lui répond. 





Explaining the factoring for the difference of cubes 
20080116 

Bill pose la question : A student asked me where did the "difference of cubes" and "sum of cubes" come from. I did not have an answer for her. She is very bright and understands how they work but wanted to know where they derived from. Any help you can offer would be great. Thanks Stephen La Rocque lui répond. 





A 16 sided lot 
20080116 

R pose la question : I am having a land of 16 irregular sides i know all the length of the sides how to calculate the
area of the land Harley Weston lui répond. 





Balancing on a fulcrum (net torque and equilbrium) 
20080115 

Eric pose la question : If I have a 4" bar that has no weight value with a 275lb. weight on one side
and a 125lb. weight on the other side what would be the folcrum point? Please
keep the answer very simple. Also is there a fixed equation to figure folcrum points?
Is there an equation for if the 4" bar had a weight value? Stephen La Rocque lui répond. 





Two solutions using the law of sines 
20080114 

Kate pose la question : I am working on the Law of Sines and I have a problem that says: Find a value for b so that the triangle has 2 solutions.
I am given that A = 36 degrees and a = 5. Now, I learned that for a triangle to have 2 solutions, h < a < b.
BUT...my answer key says the answer is: 5 < b < 5/sin 36. I can't figure out how to make this fit with h < a < b. Harley Weston lui répond. 





(303,000,000,000,303x3,300,000,033)/1,000,100,010,001 
20080113 

Adrian pose la question : Give the result of the following computation as an integer.
(303,000,000,000,303x3,300,000,033)/1,000,100,010,001
N.B. No calculators allowed Penny Nom lui répond. 





Forces on an inclined plane 
20080110 

Ron pose la question : A body that weighs 540lbs is caused to slide up an inclined plane with a uniform velocity by a force that acts parallel to the plane. For each foot of horizontal distance, there is a vertical rise of 2in. If the coefficient of sliding friction is 0.16, what force is required to move the body? Stephen La Rocque lui répond. 





Base salary plus commission 
20080110 

mike pose la question : i need some help with this word problem.
in november 2001, hall kinion advertised an account executive position in savannah
georgia for a salesperson with experience selling internet services. the job
advertised a 3500 dollar base salary and 24000 dollar to 48000 dollar in
commissions in the first year. Assuming a 20 percent commission rate, how many
dollars in sales would u have to generate to earn 64000 dollars annually. Penny Nom lui répond. 





Sqrt(x^2 + y^2) 
20080110 

Darcie pose la question : Can you simplify this problem?: square root of (x squared plus y squared).
Note: x squared plus y squared is under the radical. Penny Nom lui répond. 





Conversion 
20080108 

Dom pose la question : Hi ,
Is it possible to convert 175 grams per metered squared to cm ?
tks
Dom Stephen La Rocque lui répond. 





How far is the jet from the lighthouse? 
20080107 

Natalie pose la question : Question: A ship spots a lighthouse that is 53m high, at an angle of elevation of 7 degrees that is directly north of the ship. The same ship spots a jet travelling N62E at an altitude of 1500m with an angle of elevation of 15 degrees. How far is the jet from the lighthouse?
Natalie Harley Weston lui répond. 





Sigma notation 
20080106 

jamelia pose la question : what is this word problem in sigma style i am so lost at this point my first time ever attempting this subject
1+2+3+4+5 Penny Nom lui répond. 





Lining up coins visually using geometry and trigonometry 
20071231 

Jessica pose la question : a) In what order would you arrange a penny, a nickel, a dime, a quarter, and a halfdollar so that they all have the same apparent size? The diameters of the coins, in thousandths of inches, are as follows: penny, 750; nickel, 835; dime, 705; quarter, 955; halfdollar, 1205.
b) How should the coins be placed, if the distance between the dime and the halfdollar is 100 units?
How far from thw dime should your eye be to see that all the coins have the same apparent size?
c) What angle do the coins subtend when they have the same apparent size? Stephen La Rocque lui répond. 





Smallest cone containing a 4cm radius inscribed sphere 
20071219 

Eva pose la question : A sphere with a radius of 4cm is inscribed into a cone. Find the minimum volume of the cone. Stephen La Rocque lui répond. 





Simplifying square roots 
20071219 

Ciara pose la question : How would you calculate 2 to the square root of 8 plus 4 to the square root of 2 minus 5 to the square root of 2? Stephen La Rocque lui répond. 





What size room would I need for 220 cubic feet? 
20071218 

Andy pose la question : What size room would I need for 220 cubic feet? What is the calculation I would use to find the answer to this problem? Penny Nom lui répond. 





System of equations 
20071206 

Jenn pose la question : change the equation,xy=4 to form y=mx+b
the solution to the system of equations y=2x and y=x+3 is Stephen La Rocque lui répond. 





Chicken and goat feet 
20071205 

Kim pose la question : Old McDonald raises goats and chickens. The animals have a total of
100 heads adn 360 feet. How many goats and how many chickens does Mr.
McDonald have? Stephen La Rocque and Penny Nom lui répond. 





Third side of a triangle 
20071205 

Sudhir pose la question : How can we find the all positive integral values for the third side of a triangle, whose other two sides measure 15 and 20 respectively. (No other information viz. the type of triangle, area, perimeter or angles etc. is given.) Stephen La Rocque lui répond. 





A decision based on data 
20071204 

manny pose la question : You have administered a standardized test of manual dexterity to two groups of 10 semi skilled workers. One of these two groups of workers will be employed by you to work in a warehouse with many fragile items. The higher the manual dexterity of a worker the less likelihood that worker will break significant inventory. Because of a unique contract you must hire all 10 employees from one of the two groups and none of the employees from the other.
You must decide which group to choose. Choose at least two measures of central tendency and at least one measure of dispersion for each group and use those to make your choice. Be sure to justify your choice with at least one page of discussion and analysis. Penny Nom lui répond. 





Ramp height 
20071203 

Steve pose la question : I need to find the height of a angle.
23 degree angle at 12 feet of length is how high from the ground? Stephen La Rocque lui répond. 





Converting grams of hair spray into milliliters 
20071202 

komal pose la question : I am confused that i am converting 75grams of hair spray ( liquid) into ML? but i couldnt get the answer what is perfect answer for that please help me for this thing. Penny Nom lui répond. 





The dimensions of a box 
20071130 

nephi pose la question : if i wanted to make a box that was 0.35 ~ 0.7 Cubic Feet on the inside how would i go about making the measurements for the outside? Penny Nom lui répond. 





Transformations and compositions 
20071129 

mary pose la question : Is there any possible relationship between composite functions and the concept of function transformations? Harley Weston lui répond. 





Density 
20071129 

jessuca pose la question : what is the density for 40g / 2 mL Penny Nom lui répond. 





The width of a property 
20071129 

Angie pose la question : I need to know what the footage is to find 8.1 acres knowing that the North boundary is 1309' Penny Nom lui répond. 





The perimeter of Wisconsin 
20071126 

Kyle pose la question : I am doing a project and I need to figure out the total perimeter of wisconsin in miles
and only know the square miles of Wisconsin which is 65,503 and I need to get that to miles
I have no clue how to do this. I've looked all of the computer for answers but got none.
Thanks Leeanne Boehm and Penny Nom lui répond. 





A curve sketch 
20071122 

Ahson pose la question : Find critical points, determine the monotonicity and concavity and sketch
a graph of f(x) with any local maximum, local minimum and inflection
points labeled:
1. f(x) = x^4  x^3  3x^2 + 1 Harley Weston lui répond. 





The definition of the sine function 
20071122 

Indrajit pose la question : I need a explanation in this theory.......if sinθ = p/h...then
sin 90 deg. = p/h
or 1 = p/h
or p=h .....how can a perpendicular be equal to a hypotenuse.??? Harley Weston lui répond. 





Area of a 17sided lot 
20071121 

Lynda pose la question : My uncle is wanting to buy this piece of land [a 17sided polygon] but we are questioning the acerage total. the measurements are [on the attached diagram]. Stephen La Rocque lui répond. 





I know it's heavy, but how heavy, per linear foot? 
20071119 

Gary pose la question : I am trying to find out the weight of a linear foot of a steel bar with the following measurements.
Thickness  1.125"
Length  120"
Height  18"
Density of carbon steel  .2837
I know it's heavy, but how heavy, per linear foot? Stephen La Rocque lui répond. 





Cubic feet and gallons 
20071119 

Leonard pose la question : Every conversion I find to convert a cubic foot to a gallon is in liquid.
Question, how would 1 cubic foot convert to gallons in dry measurement?
Example say you have 1 Gallon of packing peanuts how many cubic feet would that be?
I can do this and have done it for the heck of it, I took a box 12x12x12 inches, which is a cubic foot,
filled it with packing peanuts the tried to fill a 1 Gallon container, that amount almost fills a 1 gallon
bucket twice.
I even ask a math teacher and was told that 1 cubic foot equaled 7.481 gallons,
then I said that is liquid, teacher ansered yes, then i ask what about dry and got
a response of I do not know. Harley Weston lui répond. 





Sides and vertices 
20071117 

derek pose la question : What is the correct name for a 2D geometric shape that would look like one slice from a round pizza and how may sides and vertices would it have? I believe you would say it has one vertex and two sides with the curved boundary not resulting in vertices or a side. Your help is much appreciated. Chris Fisher and Walter Whitelty lui répond. 





How many centimeters equal one meter? 
20071115 

Sherrie pose la question : How many centimeters equal one meter? Penny Nom lui répond. 





The third side of a triange 
20071112 

Christine pose la question : I need the inequality to describe the third side of a triange if two sides are known. First side is 23 and second side is 15. What is the third side? Stephen La Rocque and Victoria West lui répond. 





A mole of hydrogen peroxide 
20071111 

John pose la question : i need to get a mole of hydrogen peroxide, which i know is 34g, but i don't have a way to measure grams, so do you know how many mililiters i need to have 34g of hydrogen peroxide. Thanks for all the help Stephen La Rocque lui répond. 





How do i convert milliliters to grams for water and also for copper sulfate (CuSO4)? 
20071111 

jenn pose la question : how do i convert milliliters to grams for
water and also for copper sulfate (CuSO4)? Harley Weston lui répond. 





KWH and MWH 
20071110 

Julie pose la question : Please provide the conversion of MWH to KWH or viceversa. thanks Penny Nom lui répond. 





Cubic centimeters to cubic yards 
20071110 

Logan pose la question : if i have 188.4cm^3 of concrete how do i change it into cubic yards? Penny Nom lui répond. 





Related Rates (streetlamp and shadow) 
20071109 

Casey pose la question : A street light is mounted at the top of a 15ft pole. A man 6ft tall walks away from the pole at a rate of 5ft per second. How fast is the tip of his shadow moving when he is 40ft from the pole? Stephen La Rocque and Penny Nom lui répond. 





Increasing and decreasing for functions 
20071109 

David pose la question : Direction: Identify the open intervals on which the function is increasing or decreasing.
f(x)=1/(x^2)
f'(x)= 2/(x^3)
i understand how to get up until there, and the undf. is x=0, but now i'm having problem setting up the number table chart. i cant remember how, and where to place the increase and decrease +  the
chart, for example <0> where would the increase and the decrease be place? Harley Weston lui répond. 





Meters per second to miles per hour 
20071108 

Niecey pose la question : If Greg was timed at 0.91 seconds for 10 meters running the 100 meter dash, at that speed, could he pass a car traveling 15 miles per hour in a school zone? Penny Nom lui répond. 





Why is the number 1 neither prime nor composite? 
20071108 

amarilis pose la question : why is the number 1 neither prime nor composite? Penny Nom lui répond. 





Changing units and sizes of things 
20071108 

Carol pose la question : volume of cube = 216 cubic inches how do I calculate cubic feet and calculate its surface area in square feet.
a rectangular box has dimensions of 3 x 6 x 15 how do I calculate surface area in square yards and calculate volume in cubic inches. if I double the dimensions how does it affect the volume Stephen La Rocque lui répond. 





Simple interest 
20071108 

Lee pose la question : If a bank pays 3% simple interest anually on savings, and you did not take any money out of your account, how much money would you have deposited to earn $45 in interest Stephen La Rocque lui répond. 





Two triangles 
20071108 

Barbara pose la question : If the base of a larger triangle is 34 inches long, what is the length of side A of the smaller triangle?
(the small triangle has on top the letter a on the right side of the triangle it has the letter b, and at the bottom of the small triangle it has the number 17) Penny Nom lui répond. 





I have a piece of material 44 inches by 78 inches 
20071102 

Marianne pose la question : I have a piece of material 44 inches by 78 inches. How many linear yards can I get from it? Penny Nom lui répond. 





A decimal to a fraction 
20071101 

Lisa pose la question : i am trying to turn a decimal into a fraction. my example is to turn 10.5 into a fraction at its lowest form Penny Nom lui répond. 





A wiffleball field 
20071031 

Svitlana pose la question : The Adam's family has set up a wiffleball field in their backyard. The bases are arranged like a typical baseball diamond, where the distance between consecutive bases is the same. First base is opposite of third base, and second base is opposite of home plate. The distance between consecutive bases is 50 feet. Now, the pitcher stands 25 feet from home plate and lies on the line between home plate and second base. How far is the pitcher from first base? Round your answer down to the nearest inch. Penny Nom lui répond. 





Density 
20071030 

Ali pose la question : Would an object sink or float in pure water if it has a mass of 10g and a volume of 5 cubic centimeters?
314 Stephen La Rocque lui répond. 





Constantly accelerated motion 
20071029 

Priyanka pose la question : A, B and C are three points lying in that order on a straight line. A body is
projected from B towards A with speed 3 m/s. The body experiences an
acceleration of 1 m/s^2 towards C. If BC =20 m, find the time taken to reach C and
the distance travelled by the body from the moment of projection until it reaches C. Stephen La Rocque lui répond. 





Converting millimeteres to inches 
20071027 

Alison pose la question : I am hoping to buy a cabinet, the measurements are 1120mm x 560mm, what is that in feet & inches. Penny Nom lui répond. 





The length of a rectangle is twice the width 
20071026 

Tami pose la question : The length of a rectangle is twice the width. The number of square units in it's arear is four times the number of units in it's perimeter. What are the dimensions of the rectangle? Penny Nom lui répond. 





A sixfold increase 
20071024 

Fred pose la question : If I have $500 and it grew to $3,000, what is the correct description of the increase? Is it a sixfold increase (sextupled), or a fivefold increase (quintupled)?
When I divide $3,000 by $500, the result is six, therefore, a sixfold increase? Stephen La Rocque lui répond. 





Converting bases 
20071024 

Johanna pose la question : Is there an easy way to convert from base to base. For example, base 5 to base 9 or base 2 to base 4 etc Stephen La Rocque and Penny Nom lui répond. 





The nth term 
20071018 

shannon pose la question : Ok , what i am having problems with is the nth term. I get how the numbers come together, but i am having trouble with finding the nth term. Penny Nom lui répond. 





Convert 13.5 oz per sq yard of fabric into grams per meter square 
20071017 

marcy pose la question : I need to convert 13.5 oz per sq yard of fabric into grams per meter square. Penny Nom lui répond. 





Paying with silver  Part 2 
20071017 

Shanna pose la question : The paying with silver problem. I understand how to do the problem, but could you please explain how you would use base 2 arithmetic to solve it. Penny Nom lui répond. 





Calculate the dimensions of the rectangle 
20071016 

Sara pose la question : The perimeter of a rectangle is 62cm. The length of the diagonal is 25 cm. Calculate the dimensions of the rectangle. Stephen La Rocque lui répond. 





Surface area of an openended cone 
20071016 

Lorne pose la question : What is the surface area of an open ended cone? Measured at 10' high,
16' diameter on the bottom and 2' diameter at the top. Stephen La Rocque lui répond. 





How many tons of asphalt are in 12 cubic yards? 
20071015 

Matthew pose la question : I want to know how many tons of asphalt are in 12 cubic yards? Penny Nom lui répond. 





Four triangles in a square 
20071015 

Kristina pose la question : A square with side lengths of 6 cm is divided into 3 right triangles and a larger isosceles triangle. If the three right triangles have equal area, find the exact area of the isosceles triangle. Stephen La Rocque lui répond. 





The dimensions of a rectangle 
20071014 

Elizabeth pose la question : The perimeter of a rectangle is 20m. The area is 20sqm. Calculate the dimensions of the rectangle. Give your answers correct to two decimal places. Penny Nom lui répond. 





Substitution method 
20071011 

Kevin pose la question : 3xx+2y=36y=11 Stephen La Rocque lui répond. 





Area of a quadrilateral 
20071010 

Courtney pose la question : how would i find the area of a quadrilateral..
the sides are a (/) is 6cm, b (—) is 9 cm, and c (\) is 7 cm..
the angle between a and b is 140 degrees and b and c is 115 degrees.. Stephen La Rocque lui répond. 





Parabolic suspension bridge 
20071009 

Jessica pose la question : A suspesion bridge with weight uniformly distributed along its length has twin towers
that extend 75 meters abouve the road surfce and are 400 meters apart.The cables are
parabolic in shape and are suspended from the tops of the towers. The cables touch the road
surface at the center of the bridge. Find the height of the cables at a point
100 meters from the center. (Assume that the road is level.) Stephen La Rocque lui répond. 





Simplifying algebraic expressions 
20071009 

Sakeena pose la question : (2^2*3)^x+1/2^2x*3x Stephen La Rocque lui répond. 





Simplifying rational expressions 
20071009 

Bama pose la question : x(x2)+1 divided by x^23x+2 Stephen La Rocque lui répond. 





Subtracting rational expressions 
20071009 

Pamela pose la question : Subtract:
6p – w __ 4c + p
w – 4 w – 4
Stephen La Rocque lui répond. 





Area and side length of a hexagonal tent 
20071009 

Mark pose la question : Trying to buy a tent with 6 sides, in the catalog they give me sq. ft., what is the distance from side to side of a hexagonal tent with an area of 90 sq. ft. Stephen La Rocque lui répond. 





Coin jar 
20071007 

a student pose la question : Sally empties his jar of coins. It contains $3.75 in nickels, dimes, and
quarters. The number of dimes is twice the number of nickels and the number
of quarters is three less than the number of nickels. Determine how many nickels,
dimes, and quarters were in the in the jar. Stephen La Rocque lui répond. 





Solving four simultaneous equations (system of four linear equations) 
20071007 

Johan pose la question : I need some help in solving this question
x + 2y  3z + 4w = 12
2x + 2y  2z + 3w = 10
0 + y + z + 0 = 1
x  y + z  2w = 4 Stephen La Rocque lui répond. 





Motion along a line 
20071002 

Claudette pose la question : If the position function of a particle is x(t) = sin^2(2t), find the distance that the particle travels from t = 0 to t = 2 Harley Weston lui répond. 





3 times x to the power 2 
20071001 

Jennifer pose la question : The problem is 3 times x to the power 2.
I was just supposed to simplify, and I have no idea how. Penny Nom lui répond. 





I have a 6 digits 
20070928 

Kim pose la question : I have a 6 digits. My hundredthousands digit is 1 less that my ones digit, 8 more than my thousands digit, twice my tens digit, and 4 times my hundreds digit. My tenthousands digit is 0. What number am I? Stephen La Rocque lui répond. 





Nine dots 
20070925 

al pose la question : Connect the dots.
There is nine dots, three across and three down.
Connect the nine dot with the pencil only using four line and never lifting the pencil off of the paper. Stephen La Rocque and Harley Weston lui répond. 





Exponential regression 
20070924 

Anonymous pose la question : I need help in finding this. Find a formula for exponential regression.
Determine how to calculate a and b in the formula.
Y = ba^x
where y is as a function of x. Penny Nom lui répond. 





A 3 ounce piece of gold 
20070924 

Helen pose la question : What would the volume (in mL) of a 3 ounce piece of gold be?
16oz= 1lb
1lb= 454oz.
first i converted 3oz to lbs and then to grams to get the mass. i got 85.125 g.
now i don't know how to get the density to get to the volume. Stephen La Rocque lui répond. 





Finding equations, intersection point of two lines at right angles 
20070922 

Yaz pose la question : Find the equation of the line joining A(1,9) to B(6,120). Another line passes through C(7,5) and meets AB at rigth angle of D. Find the euation of CD and calculate the coordinates of D. Stephen La Rocque lui répond. 





Metres per minute to miles per hour 
20070920 

Angela pose la question : If a person is traveling 150 meters per minute, what is their speed in miles per hour? Stephen La Rocque and Harley Weston lui répond. 





(5C squared + 14C + 11) divided by (5C + 4) 
20070920 

John pose la question : (5C squared + 14C + 11) divided by (5C + 4) Harley Weston lui répond. 





Area of an irregular lot 
20070920 

Joanne pose la question : I found your web site through ask.com & it's great. Really hoping you can help me. We are looking at purchasing an existing home with a lot size that is advertised at 2.04 acres, however, even with my limited math skills I know this is not correct.
Their calculation takes the deepest part of the lost (179 feet) multiplied by the widest part of the lost (497.26 feet) as if it was a perfect rectangle. As you can see from the faxed diagram it is far from rectangular in shape.
Can you advise as to the true lot size? As I mentioned we are looking at this property as a purchase so time is of the essence.
I have also faxed this information (with the diagram) to the number listed on your web site. Thank you so much for your help. Harley Weston lui répond. 





how do you simplify 3a + 13b = 37 
20070916 

brandon pose la question : how do you simplify 3a + 13b = 37 Penny Nom lui répond. 





Volume, mass and density 
20070914 

Nathan pose la question : I have a sample of material that is 10cmx10cmx5cm and has a mass of 29 grams. How many grams would a sample of the same material that was 96cmx188cmx5cm be? Penny Nom lui répond. 





How much stone will be needed to fill the trench? 
20070914 

Debbie pose la question : A trench 100metres long 1ft wide*18inches deep with a 4inch pipe laid. How much stone will be needed to fill the trench.
How much weight in stone would I need to fill it? Penny Nom and Victoria West lui répond. 





Is it platinum or silver? 
20070914 

Jordan pose la question : In Chemistry we are doing a lot of problems that are much more math related than anything. One of my questions reads: A certain medallion has a mass of 55.64 g. When placed in 75.2 mL of water in a graduated cylinder,
the water level rises and then reads 77.8 mL.
Is the medallion made of platinum (D=21.4 g/mL) or silver (D= 10.5 g/mL)? Penny Nom lui répond. 





The contents of a silo 
20070914 

Steven pose la question : I need to know how to find the weight of the contents of a silo that is 4 feet across and is funnel shaped at 60 degrees Penny Nom lui répond. 





Composite angles 
20070913 

Gilbert pose la question : what is a composite angle? please help Stephen La Rocque lui répond. 





What was the water level in the cylinder? 
20070911 

glen pose la question : After a 5.63g sample of Wood's metal has been added to the water in a 10mL graduated cylinder, the new water level is 8.7mL. What was the water level in the cylinder before the sample was added? Stephen la Rocque lui répond. 





Markup to include 6% commission 
20070907 

Steve pose la question : I estimate the cost to build a house for $250,000.00. I mark it up by 20%:
$250,000 x 1.20 = $300,000 base price (BP) without sales commission. I want to set
the sale price (SP) to include a 6% commission to pay the real estate fee. After the
6 % fee is paid I want to net the $300,000 base price. The formula is basically:
$300,000 + 6% of SP = SP. But I can't figure out how to solve for SP. Penny Nom lui répond. 





2x+1+x4+4x+1 
20070906 

laurie pose la question : 2x+1+x4+4x+1 Penny Nom lui répond. 





How many two digit numbers contain at least one 7? 
20070906 

Janet pose la question : How many two digit numbers contain at least one number seven? Penny Nom lui répond. 





Variable expressions  part 2 
20070904 

lisa pose la question : how do I write a variable expression for word phrase example x less than =
2 or 2 less than p
4 fewer than job please help Penny Nom lui répond. 





Variable expressions 
20070904 

Eric pose la question : how so i write a numerical or variable expression for each quantity.
example two dozen eggs or d dozen eggs
number of quarts ub a 3 gallons Penny Nom lui répond. 





16x^2+4xy^2+8x divided by 4xy 
20070902 

Ricardo pose la question : how can i solve that problem of polynomial division?
16x^2+4xy^2+8x divided by 4xy Penny Nom lui répond. 





The quotient of thirty and ten times a number. 
20070902 

Jenna pose la question : I need help on How to translate a phrase into an algebraic expression:
The quotient of thirty and ten times a number. Penny Nom lui répond. 





george, thomas, abe, alexander... 
20070901 

lori pose la question : george, thomas, abe, alexander...
come up with the next few
im confused and need help!! Stephen la Rocque and Harley Weston lui répond. 





Similar triangles 
20070829 

James pose la question : Question: In the triangle ABC, X is a point on AC. AX = 15 m and XC = 5 m. The angle AXB is 60 degrees and the angle ABC is 120 degrees. Find the length of BC.
I am sure to an extent that this has to do with similar triangles, but I am not certain. Harley Weston lui répond. 





Converting a repeating decimal to a common fraction 
20070822 

isabelle pose la question : how do you turn 6.333... into a fraction in simplest form? Stephen La Rocque and Penny Nom lui répond. 





More on the sixth degree equation 
20070821 

Farzan pose la question : Equation 1 :
(R + (6.67*5.98*10^13/((R^2)*2)))^2  (R^2) = (7.27*(10^5)*R)^2
Equation 2 :
(6.67*5.98*10^13/(R^2*2))^2 + 6.67*5.98*10^13/R = (7.27*10^5*R)^2
As you see if we expand the left part of the first equation and simplify, the
equations become same, but these two equations have different answers in my
math software.The first one has 3 amounts for R, but the second one has 6
amounts. Why are the answers different ? Stephen La Rocque lui répond. 





A sixth degree equation 
20070820 

Farzan pose la question : Dear friends
I need to solve this equation with an understandable method for highschool students :
(6.67*5.98*10^13/(R^2*2))^2 + 6.67*5.98*10^13/R = (7.27*10^5*R)^2
please solve this problem if you have time. Harley Weston lui répond. 





The area of a five sided lot 
20070819 

Karyn pose la question : I have been looking at your site, but I am still confused as to how to
figure out the exact square footage of my irregular lot (since it is a gradual fan
lot from the front, and triangles out in the back). Harley Weston lui répond. 





What is 240mL of water in cups? 
20070816 

Gareth pose la question : What is 240mL of water in cups? Penny Nom lui répond. 





Angle of depression to a football 
20070815 

Tosin pose la question : The angle of depression to a football from the top of building 10m high
is 17 degrees. Find the distance of the ball from the foot of the building. Stephen La Rocque lui répond. 





Division by decimals 
20070815 

Brooklyn pose la question : I am studying for an exam, and I will not be able to use a calculator. I can not figure out how to do division is the number on the outside of the box is a decimal. Ex: 2/6.3=X Can you please help me figure this out? Penny Nom lui répond. 





The length of the third side of a triangle 
20070815 

Brooklyn pose la question : What is the equation to find the length of the third side of a triangle if you have the length of A, B, and the angles(s)? Stephen La Rocque lui répond. 





The tension in a single strand of wire 
20070813 

Gene pose la question : Seeking an equation that calculates the tension in a single strand of wire or rope. Conditions: the wire is fixed at both ends, A known weight is suspended from the center of the span. The weight will dipslace the strand downward some distance Y. Let the distance between the fixed ends be X= 500mm. Weight W=0.5kg. Original tension in the strand is T= 10 newtons.Your help sincerely appreciated. Gabriel Potter and Stephen La Rocque lui répond. 





Water bill woes 
20070812 

Terry pose la question : I know that a cubic foot of water=7.48051945 gals., but I keep getting my water bill and they go by thousands of a gal. per cubic foot. Is there a conversion that says that shows this? Water department=.763 x cubic foot used=thousands of gallons water used that month. Exampel: 72cu. ft meter reading x .763+ 58. galons of water I use in a month. Total 58=thousand = +gallons. This is wrong. There are only two people in the house. Stephen La Rocque lui répond. 





The swaying of a building in the wind 
20070811 

San pose la question : During a strong wind, a tall builing, such as the CN Tower, can sway
back and forth as much as 100cm, with a period of 10 seconds.
Please help me to determine the equation for this function, in the form
y=asinkx Stephen La Rocque lui répond. 





Induction  divisibility 
20070804 

Jerry pose la question : How would you prove that for any positive integer n, the value of the expression 3^(2n+2)  8n 9 is divisible by 64. Chris Fisher and Penny Nom lui répond. 





Rolling a metal plate 
20070731 

k.a.suresh pose la question : How to calculate the plate size for rolling (2010mm OD)plate thick is 6mm Harley Weston lui répond. 





Subdividing a property into half acre parcels 
20070731 

Pamela pose la question : We need to divide a large property with five sides and strange angles into 1/2 acre parcels from the top down. We want to know where along the eastern and western borders of the large property to make the divisions. Stephen La Rocque lui répond. 





Vehicle collision 
20070731 

Tania pose la question : If a driver falls asleep at the wheel of a newer model car and slams into
the rear of a parked classic mustang (28603280lb) and the parked car
is thrown 100 ft across the street, what would be the minimum speed
required by the newer car in order to move the mustang? Penny Nom lui répond. 





320 acre lots 
20070729 

melisa pose la question : we are splitting a 320 acre parcel into five 35 acre lots with one 145 ace lot. I have the footage of each side there are eight:
5280 x 2640x2640then out1320x1320up x2640back inx1320upx1320this now would meet back to the 5280foot side i know there is a half of a square mile and 320 acres.what would the measurements be in feet for length to make a square or a rectangle to make a 35 acre lot? Harley Weston lui répond. 





Angle of depression 
20070723 

joyce pose la question : hello,
here is my problem......
As you stand on a bridge w/c is 100 ft. above the water
you are looking @ an approaching barge.
If the A of top of the front of the bridge is 29.04 degrees
and the angle of depression of the rear is 17.36 degrees .
Find the length of the barge? Harley Weston lui répond. 





f(x) = (x^4)  4x^3 
20070722 

Michael pose la question : I'm a student who needs your help. I hope you'll be able to answer my question.
Here it is: Given the function f(x)=(x^4)4x^3, determine the intervals over which the function is increasing, decreasing or constant. Find all zeros of f(x) and indicate any relative minimum and maximum values of the function.
Any help would be appreciated. Thank you for your time. Harley Weston lui répond. 





Angle of depression (declination) between sailboat observations 
20070718 

Joyce pose la question : From a cliff 150 ft above a lake, we see a boat sailing directly towards us.
The angle of depression of the boat is seen to be 5 degrees and 7 inches and
11 degrees and 18 inches. Find the distance sailed between observations. Stephen La Rocque lui répond. 





The area of a property 
20070717 

Mary pose la question : I currently have an opportunity to sell my property to a business and they would like me to send a proposal to them with details.
I need to know the square footage of my property and have tried using your formula from similar questions. The dimensions of my property are as follows
front line facing street: 19.908 m
right side : 37.338 m
back line : 29.779 m
left side : 43.983m
The front line and the right side are at right angles to each other. Can you formulate and reply? Thank you Mary Harley Weston lui répond. 





Sample size 
20070717 

Nurse pose la question : If a population has standard deviation 20, what is =
the
minimum sample size to be 95% confident that the error should be =
accurate to
within 4? Harley Weston lui répond. 





Radical 96 plus radical 27 divide by radical 3 
20070717 

linda pose la question : radical 96 plus radical 27 divide by radical 3 Penny Nom lui répond. 





Trig functions for angles not between 0 and 90 degrees 
20070716 

Tim pose la question : My question: Why is the value of a trigonometric function, the same, for an angle over 90 degrees and its reference angle?
How are the angle and its reference related? Do they both form a triangle that has equal sides? Penny Nom lui répond. 





The two towers (angles of elevation trigonometry) 
20070714 

joyce pose la question : The angle of elevation of tower B from the top of tower A is 28 degrees
and the angle of elevation of the top of tower A from the base is 46 degrees
Find the height of tower A if tower B is 120 m high? Stephen La Rocque lui répond. 





Any regular polygon inscribed in a circle 
20070712 

DJ pose la question : Circle with r=12" is inscribed in a regular octagon. What is the length of each octagon segment?
Note: Our answer works for any regular polygon inscribed in any circle. Stephen La Rocque lui répond. 





Converting measurements 
20070711 

Nicole pose la question : if you have 8 oz of water how many cc: will there be. Stephen La Rocque lui répond. 





The probability of rolling double sixes twice in a row 
20070710 

Matt pose la question : what is the probability of rolling double sixes twice in a row? Stephen La Rocque lui répond. 





Grams of vodka 
20070710 

Andrew pose la question : milliliters to grams..vodka 80 proof? Stephen La Rocque lui répond. 





Derivative of a Function 
20070709 

Bob pose la question : What is the derivative of the function a sub n = [n/(n+1)]^n ? Stephen La Rocque lui répond. 





Proof that any side of a triangle is less than half the perimeter. 
20070707 

Omkar pose la question : Any side of a triangle is smaller than half of its perimeter, prove this in short ? Stephen La Rocque lui répond. 





Finding the radius of an inscribed circle 
20070705 

Maria pose la question : I need to find the radius of a circle which is inscribed inside an obtuse triangle ABC. I know all the angles and all the lengths of the triangle. Stephen La Rocque and Chris Fisher lui répond. 





Tons of concrete 
20070703 

Trey pose la question : I have 300,000 square feet of concrete and want to know how to convert this to tons? Harley Weston lui répond. 





A statistical difference 
20070703 

a student pose la question : I am writing a paper for a grad class in which I am comparing achievement levels of boys and girls. I have data that shows the average marks for girls and boys in each grade 12 subject for the entire province.
My prof want me to show there is a statistical difference. What do I have to do to show this? I don't have access to the raw data, so don't know the SD. Is there anything I can do mathematically with the data that I have? (I can determine n for each set of data, it ranges between 2400 and about 13000 for each subject area.) Chris Fisher and Harley Weston lui répond. 





Expansion on a steel boat 
20070628 

JOHN pose la question : that is the expansion on a steel boat that is 300' long by 100' wide.
if the water temp is 72deg f. and the deck temp is at 150deg f.
I think the deck would grow in all dir. and by what dist? do I still use
0.00000645 Stephen La Rocque lui répond. 





How do I convert milliliters(powder form) to grams? 
20070628 

ed pose la question : How do I convert milliliters(powder form) to grams Harley Weston lui répond. 





How do I convert inches to mm in my head? 
20070627 

philip pose la question : Hi, I would like to know how to convert inches to mm in my head, I use socket sets and want to know an easy way to work out what 3/16, 7/32 is in mm. Thanks Phil Harley Weston lui répond. 





sinx and cosx 
20070625 

Mac pose la question : Can anyone tell me whether sinx and cosx is differentiable at x=0 ?
As far as i know, cos(x) and sin(x) is differentiable at all x. Penny Nom and Stephen La Rocque lui répond. 





Volume in a triangular water trough 
20070624 

David pose la question : A water trough has sloping sides of length 500mm making it triangular in cross section, with vertical ends. The width at the top is 600mm and the length is 2.0 metres.
(i) Calculate the capacity of the trough, giving your answer accurate to the nearest litre.
(ii) Find out the depth of the water when the trough is half full. Stephen La Rocque lui répond. 





Average speeds 
20070622 

Dee pose la question : A guy goes 3.1m a second for 29 seconds in a golf cart. He then walks 1.5 meters a second. How long does he have to walk to get the average speed of 2.1m a second? Stephen La Rocque lui répond. 





Simplify 
20070621 

A student pose la question : what is the answer of
3y+5/2(4y+1)+5y/2 Penny Nom lui répond. 





Simultaneous equations : the Elimination method 
20070621 

Patricia pose la question : I need to find the value of X and Y using the Elimination method.
5/x + 3/y=4
25/x2/y=3 Stephen La Rocque lui répond. 





New wood siding 
20070620 

Angela pose la question : I have a trailer that is 14x70 and I took off the wood siding that was about 8 feet tall. They want $8.60 a cubic yard.
How many cubic yards do I have and how much will it cost me. Thanks to all! Stephen La Rocque and Penny Nom lui répond. 





Making a box with a particular volume 
20070620 

Kimberly pose la question : How do you convert 487 cf into box? Stephen La Rocque lui répond. 





How many tons of sand? 
20070619 

Richard pose la question : I need to know how many tons of sand it would take to fill a container 20 feet
long, 20 feet wide, and 6 inches deep. I am not sure of the makeup of the sand as
far as dry, loose, wet, etc. If you could give me calculations of all the variants it
would be appreciated. Stephen La Rocque and Penny Nom lui répond. 





Simultaneous inequalities 
20070618 

Freddy pose la question : Watson Electric has production facilities in Valley Mills, Marlin,and Hillsboro.
Each one produces radios,stereos,and TV sets.
There production capacities are
Valley Mills: 10 radios, 12 stereos, and 6 TV sets per hour
Marlin: 7 radios, 10 stereos, and 8 TV sets per hour
Hillsboro: 5 Radios, 4 Stereos, amid 13 TV sets per hour
QUESTION
How many hours should each plant be scheduled to fill an order of 1095 radios, 1230 stereos,
and 1490 TV sets? Stephen La Rocque lui répond. 





Simplifying a quartic rational expression using long division 
20070614 

Megan pose la question : x+2/12x^4+17x^3+0x^2+8x40= Stephen La Rocque and Penny Nom lui répond. 





The composition of functions 
20070614 

Gilligan pose la question : Question from Gilligan, a student:
Let f(x) = x^2, g(x) = 3x and h(x) = (sqrt{x}) + 1. Express each function as a composite of f, g and/or h.
(1) p(x) = 3(sqrt{x}) + 3
(2) Q(x) = (sqrt(sqrt{x}) + 1}) + 1 Penny Nom lui répond. 





Angles of depression 
20070613 

Phonda pose la question : The pilot of a small private plane can look forward and see the control tower for a small airstrip. Beyond that is a large factory that is 3 milies from the airstrip. The angles of depression are 12.5 degrees and 4.8 degrees respectively.
Find the airplane's altitude, to the nearest ten feet. Stephen La Rocque lui répond. 





Standard Deviation 
20070613 

Adrian pose la question : If you are told that the mean salary of a certain group of workers is $30,000 with a standard deviation of $4000, what proportion of workers earn over $38,000? What proportion of workers earn less than $18,000? Assume the distribution of wages is normal. Stephen La Rocque lui répond. 





Composition functions 
20070612 

Gilligan pose la question : Find functions f and g so that f(g(x)) = H.
(1) H(x) = (1 + x^2)^(3/2)
(2) H(x) = int(x^2 + 1)
I don't know where to start. Stephen La Rocque lui répond. 





Converting dollars to gallons 
20070612 

Cynthia pose la question : How do I solve this problem?
If a family uses .20 per 100 gallon of water. How many gallons would
$10.00 cost, divided amoung 3 people?
Thanks, Cynthia Stephen La Rocque lui répond. 





How high does the ladder reach? 
20070611 

Madi pose la question : A ladder 8 ft long resting on a house makes a 60 degree angle with the ground. how far up the house does it reach? Stephen La Rocque lui répond. 





The area of a quadrilateral 
20070610 

Lucy pose la question : Calculate the area of the quadrilateral ABCD.
AB= 4.1cm, BC = 7.6cm, AD= 5.4 cm, CD= ?
Angle ABC = 117, Angle ADC = 62.
Give your answer correct to 3 significant figures. Stephen La Rocque and Penny Nom lui répond. 





Rational polynomial expressions 
20070609 

a student pose la question : I have a question that continues to lead me to the answer x/(x  1) but according to my math book, the answer should be 1/(x  1).
Who is right? Who is wrong?
Here is the question:
(x^2  6x  27)/(x^2  11x + 18) DIVIDED by (x^3 + 2x^2  3x)/(x^2  2x) Stephen La Rocque lui répond. 





The law of sines 
20070609 

Felicia pose la question : A parallelogram has one side that is 12.0 cm and one angle that is 65°. The shorter diagonal is 25.0 cm. To the nearest tenth of a centimetre, how long is the other side of the parallelogram? Use the sine law. Penny Nom lui répond. 





Finding the area of a lot without knowing the angles 
20070605 

Cristin pose la question : I have a landlocked piece of land. I need to know the square
footage in order to determine the acreage. My deed only gives the lengths of its five sides. Stephen La Rocque lui répond. 





Cubic inches and square feet 
20070531 

keith pose la question : is it possible to convert cubic inches to square feet.thanx Stephen La Rocque lui répond. 





The number of grams of sulfuric acid 
20070531 

cookie pose la question : Hi,
Can you please let me know if I've done this correctly?
Calculate the number of grams of sulfuric acid in 0.500L of battery acid if the solution has a density of 1.28 g/mL and is 38.1% sulfuric acid by mass. Stephen La Rocque lui répond. 





I want to divide my land 
20070527 

alfredo pose la question : i want to divide my land. It is north is 11.86 ft, the S is 110.00 ft, the W is 644.34 ft the E is 644.58 ft. which =to1.606 acre. how many feet going from N to S would it be to make 1.5 acre Penny Nom lui répond. 





Area of a hexagon (three ways to find it) 
20070524 

Josh pose la question : I have to work out the area of a hexagon when I know that the perimeter
of it is 1000m. I have tried many different ways but I get different
answers. Stephen La Rocque lui répond. 





Simplifying a square root 
20070524 

Leigh pose la question : I am trying to help my son. Simplify sq root 81 x to the 2nd power y to the 12th power. Stephen La Rocque lui répond. 





System of equations 
20070524 

Chris pose la question : Find all real solutions (x,y,z,w) of the system of equations:
2y= x + x/17, 2z= y + y/17, 2w = z + z/17, 2x= w + w/17 Penny Nom lui répond. 





How many tons of dirt is this? 
20070523 

Deb pose la question : I need to know how many tons of dirt(6 inches deep)would it take to cover 8 acres? Stephen La Rocque lui répond. 





Converting yogurt 
20070521 

Annie pose la question : I'm trying to follow a diet plan. The diet says I should have a 125ml tub of natural low fat bio yogurt. The only problem is, the yogurt pot lists its weight as 150g (with a large 'e' after it). Can you tell me how much of the yogurt pot I'm suppost to have please, or give me a conversion chart to change from g to ml for natural bio yogurt? Stephen La Rocque lui répond. 





Converting mass of sand to volume (a sand ceremony) 
20070521 

Linda pose la question : I'm getting married. We are having a sand ceremony. The empty bottle we are using holds 800ml. I have bags of colored sand. Each bag is 30g. There is 7 people participating in this ceremony. What I need to find out is how many grams of sand i need for 7 people to participate to fill this jar. Penny Nom lui répond. 





Set up two simultaneous equations 
20070521 

Admire pose la question : The cost of producing windscreen wipers blades at a factory ais partly fixed (due to operating overheads) and partly dependent on the number of blades produced. It costs $300 to produce 1000, and $600 to produce 5000 blades. How much would it cost to produce 24000 blades? Penny Nom lui répond. 





Divisibility 
20070518 

Ashish pose la question : A number is divisible by 2^n if the last n digits of the number are divisible by 2^n.
Why? Penny Nom and Claude Tardif lui répond. 





Null hypothesis 
20070513 

Dani pose la question : A poll of 1068 American voters indicated that 48% supported te Democratic candidate for presidency. At the 0.05 level of significance, test the claim that less than 50% of American voters preferred the Democratic candidate. Penny Nom lui répond. 





Find the sample size needed 
20070513 

Mini pose la question : Find the sample size needed to be 98% confident thata marketing survey on the proportion of shoppers who use the internet for holiday shopping is accurate within a margin of error of 0.02. Assume that the conditions for a binomial distribution are met, and that a current estimate for a sample proportion does not exist. Penny Nom lui répond. 





An octagonal sign 
20070513 

Cathy pose la question : An octagonal sign is made by cutting four identical triangles made from a rectangle calculate area of one of the discarded triangles. length of square=26cmx22cm. length of octagonal sides are 10cm x 13cm Penny Nom lui répond. 





Finding the hypotenuse without Pythagorus 
20070511 

Shelbie pose la question : How do i find the hypotenuse of a right traingle not using the pythagorean thereom if i have the measurements of the legs? Stephen La Rocque lui répond. 





Angle of Elevation 
20070510 

Micky pose la question : Two Buildings are on opposite sides of a street 40 feet wide.
The taller of the two buildings is 580 feet tall. The angle of depression
from the top of the tallest building to the shorter building across the
street is 57 degrees. Find the height of the shorter building. Stephen La Rocque lui répond. 





A ton of sawdust 
20070510 

David pose la question : I am trying to do a conversion. A tractor trailer is loaded with 165 cubic
yards of sawdust (I do not know the actual weight). I knw the wholesale
cost as $1,000 for this amount, but would like to convert this to find out
what the equivalent cost for a metric ton would be. Stephen La Rocque lui répond. 





Area of irregular surfaces 
20070509 

Dustan pose la question : I am working on a way to compute very accurate
areas for irregular surfaces by using the idea of a largest possible circle... Chris Fisher lui répond. 





Converting from mm to cm 
20070508 

Amanda pose la question : How do you convert mm into centimeters? Gabriel Potter and Steve La Rocque lui répond. 





Probability of H.I.V. tests 
20070507 

Danielle pose la question : A medical test detects H.I.V. Among those who have H.I.V., the test will detect the disease with probability 0.95; among those who do NOT have H.I.V., the test will falsely claim that H.I.V. is present with probability 0.0125. Among those who take this test, 4% have H.I.V. The test is given to Lucille, and indicates that she has H.I.V. What is the probability that Lucille actually has H.I.V.? Stephen La Rocque lui répond. 





Evaluating sine and cosine 
20070506 

Selimovic pose la question : How can i solve sine or cosine for angle of, lets say 10°....Maybe
it's easy but i don't know how... Penny Nom lui répond. 





A speaker box 
20070505 

darell pose la question : I am trying to build a speaker box, and i am trying to find out the measurements of a 1.5cubic feet box. Penny Nom lui répond. 





Square footage of a lot 
20070503 

Linda pose la question : I have two lots which I am trying to calcuate the square footage of
one lot is 50 x 285.72 x 50 x 270
2nd lot is 50 x 285.72 x 50 x 277.61
Any help would be appreciated. The answers would be GREATLY
appreciated. Penny Nom lui répond. 





My commsion is 2.5% 
20070502 

susan pose la question : How do you do percentage say i sold a house for 350,000 my commssion
is 2.5% how do i figure that out can you show the formula for calculator please thank you very much Penny Nom lui répond. 





Simplify 36x squared over 18x 
20070501 

Emily pose la question : Simplify 36x squared over 18x Penny Nom lui répond. 





A tugboat's speed 
20070430 

Amanda pose la question : a tugboat must travel 24 miles against a 4 mile per hour current on the Potomac River and return. At what
constant speed must the tugboat travel to make the trip in 12 hours. Round answer to the nearest tenth mph. Stephen La Rocque lui répond. 





A couch sliding off a truck 
20070430 

William pose la question : A couch with a mass of 1 X 10^2kg is placed on an adjustable ramp connected to a truck. As one end of the ramp is raised, the couch begins to move downward. If the couch slides down the ramp with an acceleration of .70 meters per second when the ramp angle is 25 degrees, what is the coefficient of kinetic friction between the ramp and couch?
I drew a force diagram and if I did it correctly I identified the forces involved as "mg" (mass x gravity), "Fn" (normal force) and the "Ff" (frictional force). I know that we have the couch sliding down the ramp a .70 m/s but I don't think this a force and I'm not sure how this info fits into the problem. I know that the formula for calculating the coefficient of friction is Ff/Fn. Based upon the force diagram I drew and calculated Fn to be 1082N. I can't seem to get past this point. How do I determine what the frictional force is? Stephen La Rocque lui répond. 





Simplifying a rational expression 
20070429 

Tamika pose la question : X^2 + 10X + 24
______________
X + 6
SIMPLIFY EACH RATIONAL EXPRESSION (IF YOU CAN'T SIMPLIFY IT, WRITE ALREADY SIMPLIFIED) Stephen La Rocque lui répond. 





How many tons of sand is needed 
20070425 

Jennifer pose la question : How many tons of sand is needed to cover 350 cubic square feet? Penny Nom lui répond. 





How can I convert milliliters to grams? 
20070418 

April pose la question : What if I'm using cow's milk, how can I convert milliliters to grams? Stephen La Rocque lui répond. 





By how many feet was each dimension increased? 
20070418 

Becca pose la question : A rectangle is 8 feet long and 6 feet wide. If each dimension is increased by the same number of feet, the area off the new rectangle formed is 32 square feet more than the area of the original rectangle. By how many feet was each dimension increased? I need a diagram and 5 or more sentences for an explanation. Thanks! Stephen La Rocque lui répond. 





Simultaneous equations 
20070416 

kyrie pose la question : simultaneous equation
4x + 3y = 21
2x * y = 8 Penny Nom lui répond. 





Ounces and liters 
20070416 

Simone pose la question : I want to know how much is 80 ounces of water in liters? Penny Nom lui répond. 





Calculating interest 
20070415 

Gerry pose la question : Calculate the amount of interest received on £120.00 desposited in an account paying
3% simple interest for three years. Stephen La Rocque lui répond. 





The angle of depression 
20070414 

MaryBeth pose la question : Two towers are 30 m apart. From the 15th floor, 40 m up, find the angle of depression to the base of the taller tower? I think the answer is 53, but the answer book says 37. Penny Nom lui répond. 





A hypothesis test 
20070409 

Katrina pose la question : I have already tried to do this problem but im having a very had time with
it. Can you please help me.
Glamour Magazine sponsored a survey of 2500 prospective brides and
found that 60% of them spent less than $750 on their wedding gown.
Use a 0.01 significance level to test the claim that less than 62% of brides
spend less than $750 on their wedding gown. How are the results
affected if it is learned that the responses were obtained from magazine
readers who decided to respond to the survey through an Internet Web
site? Penny Nom lui répond. 





Yards of sand in a ton 
20070409 

Teresa pose la question : how many yards of sand are in a ton and how many yards of limestone does it take to make a ton Penny Nom lui répond. 





3 divided by 3 to it's fifth root 
20070406 

Annie pose la question : How do I transform the equation 3 divided by 3 to it's fifth root to simple radical form
(getting the radical out of the denominator)? Penny Nom lui répond. 





Simplify (1/3 + 1/3x) / (1/x + x/3x) 
20070404 

Farina pose la question : how do i simplify (1/3 + 1/3x) / (1/x + x/3x) Penny Nom lui répond. 





What is the intensity 5m below the surface? 
20070331 

david pose la question : I have this question which I am supposed to set it up and solve as a differential equation. I know how to solve the diffrential equation but I am having hard time understanding this question. Here is the question: The intensity of light in the ocean decreases the deeper you dive. In fact, the rate at which the intensity decreases is proportional to the current intensity. Setup the corresponding differential equation and solve for I(Y), the intensity I as a function of current intensity Y. If the light intensity 2m below the surface is 25% of the intensity at the surface, what is the intensity 5m below the surface. Can you please explain to me what does it mean by current intensity and how do I set this equation up. Thanks for the help. Penny Nom lui répond. 





The size of a lot 
20070330 

Phyllis pose la question : Could you please figure out the square footage and acreage of my lot?
One side is 480ft
One side is 410ft
One side is 480ft
The last side is 410ft
Thank you. Penny Nom lui répond. 





6 team schedule for softball 
20070329 

Angie pose la question : I have 6teams that can only play 3 days a week. Each team must get 18 games in for the season. I have to split them being the home team and the away team sometimes. Penny Nom lui répond. 





Cut a cake into four pieces 
20070327 

haley pose la question : A cake measures 10 inches x 10 inches. The cake was cut into 4 pieces that were the same size. What could the size be of each piece? Penny Nom lui répond. 





Factoring a trinomial 
20070327 

Kim pose la question : Hi, could you please help me solve this.
3x(squared) +20x  7 Leeanne Boehm lui répond. 





The distance between two fire towers 
20070323 

tony pose la question : Two fire towers are 30km apart, tower A is due west of tower B. A fire is spotted from the towers, and the bearing from A and B are N76degreesE and N56degreesW, respectively. Find the distance from the fire to the straight line connecting tower A to tower B. Stephen La Rocque lui répond. 





The law of cosines 
20070323 

chetna pose la question : Q 1) In triangle LMN, l=7, m=5 , n=4. find ANGLE N.
After applying the rule and substituting values i'm getting
Cos n= 58/40. Is there something wrong. The answer at the back of the book is 34 degrees. Penny Nom lui répond. 





Adding and Subtracting Rational Expressions 
20070321 

Pricilla pose la question : Pricilla
I do not know how to do this problem. Don't know where to start.
[(5)/(2x8)]+[(3x^2+15)/(x^34x^2+5x20)] Stephen La Rocque lui répond. 





Angles of depression 
20070321 

romaine pose la question : a woman of height 1.4m standing on top of a building of height 34.6m veiws a tree some distance away.
she observes that the angle of depression of the bottom of the tree is 35 degrees, and the angle of depression of the top
of the tree is 29 degrees. assume that the building and the tree is on level ground.
(a) calculate the distance of the woman from the top of the tree measured along her line of sight.
(b) determine the height of the tree. Stephen La Rocque lui répond. 





Synthetic division 
20070321 

Edward pose la question : Hi there,
please, explain me synthetic division of polynomial functions.
for examp.: 3x3 + 2x2 +4 divide by x2 (number after variable x is the powre of x )
Thank you. Edward. Melanie Tyrer lui répond. 





n1/(n+1)! + n+1/n! 
20070318 

Cody pose la question : How do you go about simplifying something like this;
n1/(n+1)! + n+1/n!? Steve La Rocque and Claude Tardif lui répond. 





Percentage markup 
20070316 

Debbie pose la question : What formula or formulas do I use if I want to ultimately charge a customer $300 for a service, but need to factor in a 15% commission for a sales rep, $20 to cover the cost of our overhead, the cost of a $25 coupon that we will be sending to the customer to apply to future services. In other words, what amount do I initially quote the customer to be able to cover these costs? Stephen La Rocque lui répond. 





Conversion 
20070316 

Andrew pose la question : If a lawn is 95.3 square yards, how do I convert that to square meters? Stephen La Rocque lui répond. 





Concrete sand 
20070308 

david pose la question : Can you tell me how much 4 cubic yards of concrete sand ways in tons? THANK YOU. Stephen La Rocque lui répond. 





Rotorride 
20070307 

Jessie pose la question : In a "Rotorride" at a carnival, people are rotated in a cylindrically walled "room". The room radius is 4.6m and the rotation frequency is 0.550 revolutions per second when the floor drops out. What is the minimum coefficient of static friction so that people will not slip down? People on this ride say they were "pressed against the wall". Is there really an outward force pressing them against the wall? If so, what is its source? If not, what is the proper description of their situation (besides scary)? Stephen La Rocque lui répond. 





The volume of a trailer 
20070304 

Ron pose la question : I just can not seem to work this out, i think it is old age catching up with me, I am buying a trailer that is 25 feet long 7.5 foot wide and with 4 foot sides and i am trying to work out how many m3 it will hold can anyone help. Thank you in advance for any help. Regards Ron Penny Nom lui répond. 





A square 
20070302 

Jake pose la question : how many sides does a square have? Sara Ulmer lui répond. 





Grams to millilitres 
20070302 

anton pose la question : I am trying to convert 28 grams of weight loss powder into mils Gabriel Potter lui répond. 





Mutually exclusive events 
20070301 

kalyssa pose la question : will you me an example of two events that are mutually exclusive and could you explain to me what mutually exclusive means? Steve La Rocque, Pam Fowler and Penny Nom lui répond. 





How many yards of concrete? 
20070228 

jeremy pose la question : I need to figure how many yards of concrete to use. I work for an asphalt company, and we are expanding into concrete. Currently we measure everything in sq. ft. So we came up with 6,960 sq ft of concrete to remove and replace. Currently there is 6" of concrete, and 2" of bedding material. We would like to replace only 4.5" of concrete, the rest in bedding. Here is how I figured, am I correct. 6,960 Sq ft (to simplify I made the Sq ft 350 X 20 ) 350 ft X 20 ft X .33 (1/3 ft or 4") = 2,310 cubic feet 2,310 cb ft / 27 = 85.55 cubic yards Is this correct? Penny Nom lui répond. 





Simultaneous equations with fractions 
20070228 

Alyca pose la question : Hello Math Central, I am a grade 10 student taking Academic math. Our unit right now is method of substitution and elimination. I'm stuck on this one question that I've been doing forever. Please help =)
*For this equation I have to do method of elimination, but it's so much harder with fractions...could some one please explain to me how to do it step by step?* x y 2    =   3 6 3 x y 1    = 1 12 4 2
Steve La Rocque and Ashley Mang lui répond. 





Similar triangles 
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Vivienne pose la question : The lengths of the sides of a triangle are 8, 15, & 17. If the longest side of a simlar triangle is 51, what is the length of the shortest side? Stephen La Rocque and Penny Nom lui répond. 





The length of the side of a hexagon 
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Nick pose la question : if the area of a regular hexagon is 259.807 how do i find the length of each side, and the apothem? thanks if you can help Penny Nom lui répond. 





What is the remainder when 3^2007 is divided by seven? 
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Chris pose la question : What is the remainder when 3^2007 is divided by seven?? Leeanne Boehm lui répond. 





Optical illusions 
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Jami pose la question : Hi, I'm Jami and I'm in 10th grade.I'm doing a geometry research project on optical illusions and need to know how math is involved.I have an idea already of how our eyes percept 2 dimensional images and construct them into 3D images but, that isn't my question.There are many books that contain optical illusion pictures that have secret messages in them or have objects popping out. Is there a mathematical way in that optical illusion pictures are constructed? Walter Whiteley and Harley Weston lui répond. 





A gymnast is swinging on a high bar. 
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William pose la question : A gymnast is swinging on a high bar. The distance between his waist (center of mass) and the bar is 1.1 m. If his speed at the top of his swing is zero and his gain in speed is due entirely to his change in gravitational potential energy, find his speed at the bottom of his swing. Stephen La Rocque lui répond. 





Centimeters to cubic meters and grams to kilograms 
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Colleen pose la question : A box of balls measures 120cm by 20cm by 20cm and weighs 48 g. One thousand boxes = x cubic meters and weighs x kilograms. Also, one million boxes = x cubic me 