The Four Chocolate Coins
Discrete Mathematics
Level
3
Alexane has four chocolate fair coins.
She flips all the coins and eats those that fall on head.
She flips the coins not eaten (those that fell on tail) a second time and eats those that fall on head.
What is the probability that Alexane has eaten more than 2 coins?
If the probability can be expressed as \( \dfrac ab\), where \(a\) and \(b\) are coprime positive integers, find \(a+b\).
by
Paul Fournier