Rolling a Number Cube

Date: 02/27/2002 at 19:34:22
From: Jennifer
Subject: Probability word problem

Here is a word problem my 4th grader brought home from school. 
I can't figure out how to solve it.

A number cube is labeled with the numbers 3,6,9,12,15,and 18.  
Describe an outcome of rolling the cube that has a probability of 3/6.

Date: 02/27/2002 at 21:12:04
From: Doctor Twe
Subject: Re: Probability word problem

Hi Jennifer - thanks for writing to Dr. Math.

Any characteristic that describes exactly 3 of the 6 numbers will do. 
Here are several examples:

 - rolling a number less than 10
 - rolling a multiple of 6
 - rolling an even number
 - rolling a 3, 12, or 15
 - rolling a number, which when divided by 3, yields a prime number

There are, of course, many other outcomes that have a probability of 
3/6, but I hope that these examples clarify what is meant.

I hope this helps. If you have any more questions, write back.

- Doctor TWE, The Math Forum
  http://mathforum.com/dr.math/