Question

In how many ways can you select a committee of four students of a group of nine students?

Answer 1

126

Explanation:

n! / (r! (n-r)!)

In this case n = 9 and r = 4

9!/ (4! * (9-4)!)

9!/ (4! * 5!)

= 126

9! = 9x8x7x6x5x4x3x2x1