Question

A ballroom dance couple has learned 13 different routines and needs to pick 9 of them to prepare for an upcoming local competition. How many different ways could they choose which dances to prepare?

Answer 1

259459200

Explanation:

They have 13 choices for the first one, 12 for the second one, 11 for the third one, etc.

So, they have 13*12*11*10*9*8*7*6*5 = 259459200 ways.