Question

Jessica wants to take three books on vacation with her. She has five books to choose from. How many possible combinations of three books could she take on vacation?

Answer 1

We use the combination formula:

combinations = n! / r! * (n-r)!

n = 5 and r =3

combinations = 5! / 3! * 2!

combinations = 5! / 12

combinations = 5 * 4 * 3 * 2 * 1 / 12

combinations = 5 * 2 = 10

Explanation:

Answer 2

It would have to be 3/5