







Macy's coin collection 
20190130 

From Sariah: Macy's coin collection has 2 pennies for every nickel. If she has 60 coins that are pennies or nickels, how many nickels does she have? Answered by Penny Nom. 





Nickels, dimes, and quarters 
20180420 

From Patti: A copy machine accepts nickels, dimes, and quarters. After 1 hour, there are 30 coins total, and their value is $5.10. How many nickels, quarters, and dimes are in the machine? (Hint: There are exactly five different solutions.) Answered by Penny Nom. 





Five coins 
20171110 

From Allan: I have five coins..a penny,a nickle,a dime,a quarter and a loonie.....how many different amounts of money could i pay using ny combination of this coins Answered by Penny Nom. 





Dimes and pennies 
20160426 

From Renae: Charity has 42 more pennies than dimes. Hope has 7 times as many pennies than dimes. Hope and Charity have the same number of dimes. Together they have $5.46. How many dimes and pennies do each have? Answered by Penny Nom. 





$9.50 in coins 
20140115 

From dana: you have $9.50 in coins. it has twice as many nickels as quarters and three times as many dimes as nickels. how many of each coin do you have? Answered by Penny Nom. 





Drawing three coins from 10 coins 
20110929 

From Michelle: Three coins are chosen at random from a purse containing 6 dimes & 4 quarters. What is the probability that the selection will contain at least one quarter? Answered by Penny Nom. 





A coin toss game 
20110829 

From Aniish: A and B alternately toss a coin.The first one to turn up a head wins.If no more than 5
tosses each are allowed for a single game,find the probability that the person who tosses
first will win the game?What are the odd's against A losing if she goes first? Answered by Penny Nom. 





Three tangent circles 
20110819 

From hanniel: two coin are tangent to a third coin internally and are tangent to each other
externally. The distance between their centers are 14 mm, 17mm, and 5mm.
find their radii Answered by Penny Nom. 





Four coins 
20110311 

From Nestor: exact amount: philip has a quarter, a dime, a nickel, and a penny. for how many different prices could he give the exact amount? Answered by Penny Nom. 





12 coins 
20100707 

From Eden: We have 12 coins same in size and shape and also weight.
But among these, one coin which has same size and shape, but not in weight
and we can't know that this coin was lighter or heavier.
We must decide which coin was lighter or heavier among these 12 coins in
4 times of weighting with scale. Answered by Stephen La Rocque and Tyler Wood. 





Sarim has $1 in coins. 
20091027 

From Elizabeth: Here is the question asked: Sarim has $1 in coins. Onefifth of the coins are dimes, twofifteenths are nickels, and twothirds are pennies. Tell how many of each coin he has. I am not sure how to start this problem. Answered by Penny Nom. 





$6.25 in nickels quaters and dimes 
20091010 

From miriam: a piggy bank contains $ 6.25 in nickles quaters and dimes.
there are 65 coins all together and there are four times as many nickles as quaters
find the number of coins of each kind Answered by Penny Nom. 





Toss a coin and roll a die 
20090921 

From Celeste: 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? Answered by Penny Nom. 





Tossing a penny 26 times 
20090804 

From Basma: Jack is going ot toss a penny 26 times.
How many times should it land on heads? Answered by Robert Dawson. 





A bag of coins 
20090109 

From marina: I have a bag of gold coins. I give 1/8 to mother then gave 1/2 of what was left to my brother
i give 2/7 of what was left to father. If i have 25 coins left. how many do i have originally. Answered by Robert Dawson and Penny Nom. 





50 coins with a value of $1.00 
20090108 

From Ana: you have 50 coins which have a total value of 1.00. What are the coins and how many of each do you have? Answered by Robert Dawson. 





Nickels, dimes and quarters 
20081027 

From val: I would like help working out a math word problem. A collection of 30 coins worth $5.50 consists of nickels, dimes, and quarters. There are twice as many dimes as nickels. How many quarters. Could you teach me how to find this formula? Answered by Penny Nom. 





Abby has 45 coins 
20080828 

From Sonia: Use an algebraic approach to solve the problem. Abby has 45 coins, consisting only of dimes and quarters, worth $6.6. How many dimes and how many quarters does she have? Answered by Penny Nom and Victoria West. 





A fivesided coin 
20080629 

From carla: A new fivesided coin is to be made in the shape of figure 8.6
The point A on the circumference of the coin is the centre of arc CD, which has a radius of 2cm
Similarly B is the centre of arc DE, and so on.
Find the area of one face of the coin. Answered by Harley Weston. 





Tossing a coin 
20080125 

From Christopher: Jack tosses a coin 30 times. How many times would you expect the coin to land tails side up? Answered by Harley Weston. 





Lining up coins visually using geometry and trigonometry 
20071231 

From Jessica: 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? Answered by Stephen La Rocque. 





Nickels, dimes and pennies 
20071014 

From tom: you have $1.00 and 1/5 of it is dimes, 2/15 is nickels, and 2/3 is pennies. How many coins of each are there. how do i set it up to solve this problem. thanks, tom Answered by Penny Nom. 





Coin jar 
20071007 

From a student: 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. Answered by Stephen La Rocque. 





Surface area of a coin 
20070705 

From Anne: Assuming both sides of a coin are identical, and a line tangent to the inner circle is 23 mm from edge to edge of the coin, and excluding the edge of the coin in the calculation, what is the surface area of the coin, in square millimetres? Answered by Stephen La Rocque. 





A counterfeit coin 
20070305 

From Delian: Hi there, I have a counterfeit penny problem  however this one is slightly more challenging. I have twelve pennies, and one of them is counterfeit. The only difference between the counterfeit coin and the real ones is that the counterfeit is EITHER heavier or lighter than the others (We don't know which). I need to be able to solve this in only three weightings, and I REALLY NEED HELP!!! Answered by Penny Nom. 





Weightng coins 
20070218 

From Gary: You are considering buying 27 silver coins that look alike, but you have been told that one of the coins is a lightweight counterfeit. Find the least number of weighings on a balance scale that you can use to be certain you have found the counterfeit coin. Answered by Penny Nom. 





Nickels, dimes and quarters 
20070205 

From Avinash: Mary has 48 coins made up of nickels, dimes and quarters with a total value of $5.10. She has 4 more dimes than nickels and quarters combined. How many coins of each kind does she have? Use matrix to solve the system Answered by Stephen La Rocque. 





Place value, coins and money 
20061212 

From Emily: I was wondering what the best way would be to teach place value using coins and money. I have used base ten blocks already and am looking for a way to integrate money, perhaps on a place value chart and perhaps using decimals. Answered by Diane Hanson. 





A jar contains 36.25$ 
20060612 

From Brunia: A jar contains 36.25$ in pieces of 0.10 and of 0.25$. If it there has 250 change pieces in all, how much there he has pieces of 0.25$ in the jar. Answered by Penny Nom. 





Flipping a coin 
20060608 

From John: If a coin is flipped n times, where H is the number of heads after n flips, and T the number of tails, then will the quantity (HT) change signs infinitely often as n goes to infinity? Answered by Chris Fisher. 





Oddman out coin tossing and probabilities 
20060427 

From Kalyan: When four people toss fair coins, what is the probability that in a given toss there will be one "odd man". That is one person whose coin does not have the same out comes as that of any other members? Answered by Stephen La Rocque. 





A triangle of 50p pieces 
20060222 

From Stuart:
Ok, so i am collecting 50p pieces and arranging them on my desk in the shape of a triangle.
eg
50p
50p 50p
50p 50p 50p
50p 50p 50p 50p
I want to work out how much money I'm saving just by knowing how many rows of coins there are. If i can work out how many coins there are just by knowing how many rows I have I can just divide by 2 to find out the amount in dollars.
Answered by Penny Nom. 





112! 
20040528 

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





A counterfeit coin 
20040123 

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





Arithmitic sequence 
20030201 

From A student: I am having problems solving this arithmetic sequence... 1, 5, 10, ___, 50, 1.00, ___, 10.00, ... I believe the answers to be 25 and 5.00 but I can't figure why. Answered by Claude Tardif. 





A penny, a nickel, a dime, a quarter, and a loonie 
20030121 

From Blaine: I have 5 coins: a penny, a nickel, a dime, a quarter, and a loonie. How many different amounts of money could I pay using any combination of these coins? Answered by Penny Nom. 





A coin is tossed 11 times 
20021031 

From A student: There are 2 people that are playing a game in which a coin is tossed 11 times. The first player gets a point for a toss of heads. The 2nd player gets a point for a toss of tails. whoever gets 6 points wins. Suppose that so far the first player has 2 points and the second player has 4 points. What is the probability that the first player wins the game? Answered by Andrei Volodin and Penny Nom. 





Piles of coins 
20011205 

From A student: Sharon has less than 20 coins. When she puts them in piles of 5, she has 1 left over. When she put them in piles of 3, she also has 1 left over. How many coins does Sharon have? Answered by Penny Nom. 





Lots of coins 
20010426 

From A student: I purchase 2 million coins at 9.75 I purchase 1 milion coins at 8 what is the formula to calculate my average cost? Answered by Penny Nom. 





Coins and monomials 
20010304 

From A student: Tokola has 5 coins with a total value of $1.05. He canot make change for a dollar, 5 cents, 10 cents, 25 cent, or 50 cents. What 5 coins does he have? and Determine whether 6cd is a monmial. Explain why or why not. Answered by Penny Nom. 





Rolling Circles 
19990912 

From Craig Ellis: We have a circle of radius 3. inside the circle and tangent to the circle of radius 3 at one point is a circleof radius 1. The question is if we could roll the smaller circle around the inside of the larger circle how many revolutions would it take to get around to where we started. Answered by Chris Fisher and Walter Whiteley. 





48 cents with 6 coins 
19990505 

From Belinda: i'm in 5th grade. my teacher asked this question: what are two ways you can make 48 cents out of 6 coins? i could only figure out one way. please help. Answered by Chris Fisher. 





A balance problem 
19961118 

From Jack N. Bussell: There are 12 coins which look exactly the same, however one of them is heavier or lighter than the rest. Using a pointer balance scale, can you identify the odd coin and whether it is heavy or light in 3 weighings? Answered by Harley Weston. 





A coin problem 
19960416 

From Julie Hebert and Simon Hamel: How many weighings would you need to find out which pile is fraudulent? Answered by Penny Nom. 

