







Solides d’Archimède 
20140429 

Clémentine pose la question : Pourquoi une pyramide a base carrée n'est elle pas un polyèdre archimedien ?
J'ai pourtant essayé d'en construire un avec tout ses cotés égaux et ça fonctionne !
Aidez moi je n'en dors plus la nuit ? :S Chris Fisher 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. 





Gradient 
20140221 

Nancy pose la question : calculate the gradient of the line AB when the line AB is passing through the points A (2,1,) and B ( 4, 3).) Penny Nom lui répond. 





One in twenty as a percentage 
20100427 

jim pose la question : Please advise how I work out a gradient of say 120 one in twenty as a percentage % Penny Nom lui répond. 





A single die is rolled twice 
20091103 

Michelle pose la question : A single die is rolled twice. Find the probability of getting two numbers whose sum exceeds 5.
I can't seem to come up with any of these answers, Help. A. 0.72 B. 0.89 C. 0.68 D. 0.58 Penny Nom lui répond. 





Toss a coin and roll a die 
20090921 

Celeste pose la question : Can you please tell me how to set up this problem to find the answer. I know they are independent from there I don't know.
a coin and a regular sixsided die are tossed together once. What is the probability that the coin shows a head or the die has a 5 on the upward face? Penny Nom lui répond. 





A slopped table top 
20090316 

anthony pose la question : A perfect circle with radius 100m is supported by four legs, 50m long. The circle is flat when all four legs are 50m long, and tilted when the legs are different in length. The four legs are spread evenly 90 degrees apart at 0, 90, 180, and 270. Find the high and low points in degree and height when the legs are 55m at 0 degree, 70m at 90 degree, 45m at 180 degree, and 30m at 270 degree.
Not sure if they can be calculated using only 2 or 3 legs.
I have tried by picking the two adjacent highest legs (55m and 70m) so I know the high point falls into the first quadrant. Then I tried using ratio to determine where the high point is, which I think high point should be closer to the 70m leg, I am not sure. If I can find the high point, the low point should be opposite to it. Chris Fisher and Harley Weston lui répond. 





A die is loaded so that... 
20090130 

Larry pose la question : Hi. I'm having trouble solving this problem. Would you be kind enough to point me in the right direction?
A die is loaded so that the probability of a particular face rolling up is proportional to the number of dots
on the face. In other words, getting a six is three times as probable as getting a two. what is the probability
of getting an even number in one toss? Victoria West lui répond. 





A spill of oil on a flat surface 
20081219 

Phillip pose la question : Hello, my question is: If I spilled 25 gallons of diesel fuel on a flat surface how much area would the spill cover?
How would I mathematically figure it out?
Thanks! Robert Dawson and Harley Weston lui répond. 





The amount of diesel fuel in a tank 
20081026 

Mike pose la question : I have an cylinder shaped oil tank that holds approx. 283 gals of diesel fuel. The tank is laying on on its side, (like taking a garbage can and laying it down on its side). What is the formula to calculate how much oil is in the tank at any given time. If the tank was sitting on end it would be easy to figure out, but it is not. Stephen La Rocque lui répond. 





Rolling a die repeatedly (you can't just add percentages) 
20071004 

Howard pose la question : If my son has a 16.66% chance of rolling a particular number on a dice,
and he rolls for it 6 times, he knows (from experience) that his
odds of getting at least 1 right are not 100% (16.66% +16.66%+16.66% etc).
He asked me if there was an equation that would give him the correct
percentage chance of success when trying X times for a Y% chance
of something. Victoria West lui répond. 





livinia the housefly finds herself caught in the oven 
20060627 

Danielle pose la question :
livinia the housefly finds herself caught in the oven at the point (0,0,1). the temperature at the points in the oven is given by the function
T(x,y,z) = 10 (xe^{(y2)} + ze^{(x2)})
where the units are in degrees celsius.
(i.)so if livinia begins to move towards the point (2,3,1) at what rate in deg/cm does she find the temp. changing?
(ii.)in what direction should she move in order to cool off as rapidly as possible?
(iii.)suppose that livinia can fly at a speed of the square root of 2 (cm/sec.) if she moves in the direction of part (ii) at what rate will she find the temp. to be changing?
Penny Nom lui répond. 





A probability question which resulted from a game of Yahtzee 
20051231 

Robert pose la question : Could someone please assist me with this probability question which resulted from a game of Yahtzee we were playing in Melbourne, Australia on our holidays.
The object on this turn was to throw a “large straight” which is 5 numbers in sequence from 5 dice numbered 1 – 6. A player initially throws all 5 dice and then selects those dice they want to throw again for a further two more times. In this instance the player on their first throw, threw a 1,2,3,4 and 6.
Question: What is the respective probabilities of gaining a straight if they were to –
a) put back say the 6 and try and throw a 5 on the two further throws or…..
b) put back the 1 and 6 and try and throw a 1 and 5 or 5 and 6 on the two further throws bearing in mind that if one of the numbers was a 5 on the second throw they could hold that number and try for a 1 or 6 on the third throw.
I would be most appreciative if someone could assist in showing me how to calculate the probabilities particularly in the second instance (b). Penny Nom lui répond. 





Four 25sided dice 
20051124 

dan pose la question : Simply put, I am curious to find the likelyhood of each possibility (4100) if I were to roll 4 25sided die. It seems to start off simply, as 1, 4, 10, 20...following the inside diagonal of Pascal's triangle. But as soon as i reach the point where the sum is greater than the number of sides, Pascal's no longer seems to work. I would be greatly appreciated if I could be informed of the proper formula to find this answer, or perhaps if my theory of doing it is wrong. Andrei Volodin and Shaun Fallat lui répond. 





Biodiesel 
20050308 

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





The gradiant of a hill is 9% 
20041218 

Jim pose la question : The gradiant of a hill is 9%. What angle is created by the run/rise of the hill and 0 degrees? Penny Nom lui répond. 





Marching legion 
20040424 

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





Sasha's candies 
20030218 

Pat pose la question : Ticktactoe
Sasha and Trudy are playing ticktactoe. Sasha agrees to give trudy two pieces of candy for each game Sasha loses, and Trudy agrees to give Sasha three pieces of candy for each game that Trudy loses. After playing thirty games, Sasha has the amount of candy that he started with. If no ties occurred, how many games did Sasha win? Paul Betts lui répond. 





A game of dice 
20020513 

Mika pose la question : To play a game a dice is rolled to see who plays first. four players are going to play the game. what is the probability that at least two people roll the same number? ANSWER: P(least 2 people roll the same #)=number of player/total outcome P = 4!/4C2 = 24/4C2 = 4 the answer is 40% Andrei Volodin lui répond. 





A probability tree 
20020504 

A student pose la question : Karl and Naomi roll three dice. Karl gives $10 to Naomi if the number 5 turns up once, twice or three times. Naomi gives Karl $3 in all other cases. A) construct the probability tree for this situation.
B) Does Karl have an advantage in this game? Justify your answer. My problem is I am unfamiliar on how to draw this probability tree and seem to be having a lot of difficulties, when you have a chance please answer this math problem and get back to me with the results. Penny Nom lui répond. 





Rolling two dice 
20010910 

Owen pose la question : This probability question has been bugging me for a while. Two ordinary dice are rolled. If it is known that one shows a 5, what is the probability that they total 8? I have two different but (seemingly) correct solutions. Andrei Volodin lui répond. 





Mutually exclusive 
20010605 

Marje pose la question : What does the mathmatical term "mutually exclusive" mean. Pleas diagram if possible. Penny Nom lui répond. 





Probabilities and dice. 
20010504 

Carmen pose la question : Hi! My name is Carmen! I am a member of a grade 5 class in Edmonton, AB. We were talking about probability in math, and I was wanted to know what the probability (odds) of rolling two sixes would be rolling two dice? If it is not to diffucult could you tell me what the probability (odds) of rolling any number with two dice were? Andrei Volodin and Penny Nom lui répond. 





Expected value 
20010424 

Cindy pose la question : A game consists of rolling a single fair die. If a number great than 4 is rolled you win the number of dollars showing on the die. If any other number is rolled, you receive $1.00. What is the expected value of this game? Andrei Volodin lui répond. 





Motivators 
20010116 

Michelle Stapley pose la question : Do you know of any (or where I can find) student motivators for math at the secondary level? Basically any way I can motivate my students to WANT to learn math. Penny Nom lui répond. 





Three dice 
19981117 

Ryan Allinson pose la question : Rolling three regular dice how many different ways could a sum of 10 be rolled? Hope you can help. Can you please show me how this is done? Penny Nom lui répond. 





Snake Eyes 
19980720 

Would you please advise me what the probability is of rolling snake eyes on a pair of dice is? My recollection is 1 out of 6 multiplied by 1 out of 6 = 1 out of 36 is this correct? Jack LeSage and Penny Nom lui répond. 





Rolling a seven 
19980611 

Bruce Thompson pose la question : What is the probablity of rolling two dice and it coming out as seven? a) 1/6 b) 1/36 please give me the correct awnser and explain please. Harley Weston lui répond. 

