







Drawing a counter from 2 bags 
20200521 

From Sephy: Question 4: Two bags, 1 and 2, each contain equal size counters.
Bag 1 contains a pink counter, yellow counter and white counter.
Bag 2 contains counters labelled 1, 4, 5 and 7.
A counter is drawn at random from bag 1
and a counter is drawn at random from bag 2.
If the counter from bag 1 is pink, the number on the
counter from bag 2 is increased by 1
If the counter from bag 1 is yellow, the number on the
counter from bag 2 is decreased by 5
If the counter from bag 1 is white, the number is halved.
Find the probability of scoring a number below 3 Answered by Penny Nom. 





Golf for 6  2 three balls 
20160201 

From Andy: We are shortly having a golf holiday in Phoenix. There are 6 people playing 6 rounds, so we will play in 2 three balls. Is there a combination of pairings that ensures everyone plays with each other the same number of times. Many thanks for your help ! Andy Answered by Victoria West. 





20 golfers playing four rounds 
20150817 

From Paul: I have a party of 20 golfers playing four rounds in fourballs.
I realise that everyone will have 7 players that they do not play
with, however I want to ensure that no one plays with the same
person twice and that the Captain plays with the 12 players of
his choice. Answered by Victoria West. 





What is the probability that the sixth draw will be a red ball? 
20121123 

From Patty: The probability of drawing a red ball out of a bag containing one red ball and one black ball is 1/2. An experiment is conducted where these two balls are placed in a bag before drawing a ball out. A ball is drawn 5 times from the bag containing the two balls. Each of the first five times the red ball was drawn out. what is the probability that the sixth draw will be a red ball? Answered by Penny Nom. 





Three tennis balls 
20120517 

From eiman: Three tennis balls are placed inside a container . the tennis balls are tangent to the top, bottom,and sides of the container . find the volume of air inside the container surrounding the tennis balls if the diameter of the tennis balls is 6 inches Answered by Chris Fisher. 





Golf: 8 players over 4 days in 4balls 
20120503 

From JimB: I cannot seem to get this to work. Previous answers cover 2balls, but we are 4balls.
What we really want is for each player to play with each other, at least once and no more than twice.
Ideally, each would also play equally in the first and the second 4ball of the day. Answered by Victoria West. 





There are 12 balls and one balls weight is different than the others 
20100812 

From david: if there was 12 balls and one balls weight is different than the other and use a balance 3 times is there a possible way to find which weigh different Answered by Robert Dawson. 





Packing spheres in a given region 
20100127 

From MISAEL: IN A VOLUME GENERATED BY TWO TRAPEZOIDS WITH DIFFERENT SURFACE AREAS BUT SHARING THE BOTTOM PLANE:
HOW CAN I CALCULATE THE "N" SPHERES WHICH THIS VOLUME CAN CONTAIN?
HOW CAN I CALCULATE THE VOLUME OF SPACES IN RELATIONSHIP WITH VOLUME OF SPHERES OR THE TOTAL VOLUME? Answered by Robert Dawson. 





Balls and cubes in an urn 
20080909 

From Dave: In an urn, there are 80 objects of two kinds: cubes (C) and balls (B). An object can be either red (R) or green (G).
Note that all the four combinations are possible and that the number of cubes is not necessarily equal to the number of
balls. Similarly, the number of red objects is not necessarily equal to the number of green objects. Someone tells us that
in the urn there are 20 red cubes, 50 balls, and 30 red objects. An object is randomly selected from the urn.
(a). What is the probability that a green ball is selected?
(b). If we know that a cube has been selected, what is the probability that it's red?
(c). If we know that a red object has been selected, what is the probability that it's a cube? Answered by Harley Weston. 





Volume of a tennis ball can 
20060416 

From Jon: Tennis balls are generally packaged in circular cylinders that hold 3 balls each. The diameter of a tennis ball is 6.5 cm. Find the volume of a can of tennis balls. Answered by Stephen La Rocque. 





Balls in a cylinder 
20060303 

From Roxanne: If a cylindrical can holds three balls with no room to spare, explain how to find the volume of the air that surrounds the balls in the can. Yet the balls have a diameter of six inches Answered by Stephen La Rocque. 





Twelve golf balls 
20051228 

From Todd: You have 12 golf balls and 11 of them are the exact same weight, but one of them is either a little heavier or a little lighter. You only have three attempts to weigh the balls. How can you determine which ball weighs more/less than the rest? Answered by Penny Nom. 





Tennis balls and probability 
20041101 

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





Forty balls are placed in a bag 
20040619 

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





Selecting balls from a golf bag 
20040221 

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





Distributing r identical balls into n distinct boxes 
20030316 

From Diana: How many ways to distribute r identical balls into n distinct boxes with exactly m boxes empty? Answered by Penny Nom. 





Manufactures golf balls 
20011106 

From Kevin: A company manufactures golf balls. Golf balls are each numbered consecutively 0 to 4, and then the numbering starts over with zero again. Every 12th golf ball is yellow. Every 8th golf ball is tested for defects. The company produces 120,000 golf balls in an eighthour shift. A. How many yellow golf balls are tested for defects during the day? Explain your reasoning. B. How many of these yellow balls that are tested are imprinted with the numeral 2? Explain your reasoning. Answered by Penny Nom. 





Buckets of golf balls 
20010208 

From A student: A bucket containing 40 golf balls weighs 135 ounces. The same bucket with 20 golf balls weighs 75 ounces. What is the weight of the bucket? Answered by Claude Tardif. 





Cannonballs 
19990127 

From Roger King: How many cannonballs can be stacked in a triangular pyramid? Answered by Penny Nom. 

