Billy has a die. He rolls the die, and if the result is not even, he rolls the die
one more time. Find the probability that he ends up with an even number.
If he has a die then it is 6 sided. He has a 1/2 chance the 1st time that he gets a non-even number. The next time he also has a 1/2 chance of getting an even number so it's 1/2 times 1/2 = 1/4.
