Question

At a high school, 9 students volunteer for a committee. How many different 4 -person committees can be chosen?

Answer 1

126 ways

Explanation:

Total number of persons = 9

Number of commitees to be chosen = 4

Since, there is no order in the selection process, we use combination.

Choosing a committee of 4 from 9 will be :

9C4.

Recall :

nCr = n! / (n-r)!r!

9C4 = 9! / 5!4!

9C4 = (9*8*7*6) / (4*3*2*1) = 3024 / 24 = 126 ways