Question

A theater company with 9 actors is putting on a play that has 3 roles. In how many different ways can the director assign actors to those roles?

Answer 1

This is a permutation:
9P3

The formula is n! / (n-r)!

Answer 2

9! / (9-3)!
9! / 6!

9 * 8 * 7
72 * 7
504 is the answer