2005 CEMC Pascal Problems/Problem 4
Problem
Six balls, numbered are placed in a hat. Each ball is equally likely to be chosen. If one ball is chosen, what is the probability that the number on the selected ball is a prime number?
Solution
To find the probability of the ball having a prime number, we can find the number of ways that we can select a ball with a prime number divided by the number of balls.
From the list, the prime numbers are and
. This gives us
ways to select a ball with a prime number on it.
Dividing this by the number of balls, we have;
~anabel.disher