Mom has 2 apples and 3 bananas. Every morning for 5 days she is going to give her son an apple or a banana.

Question

What is the probability that the boy will get a banana at least two days in a row during these five days?

Answer 1

number of ways to give the fruits
= 5!/(3!2!) = 10
(you could list them)

Bananas at least two days in a row:
BABAB is the only case where two or more B could not be together. Look at your list from above

prog(at least two B's in a row) = 9/10

Answer 2

9/10