From 9 names on a ballot a committee of 3 will be elected to

From 9 names on a ballot, a committee of 3 will be elected to attend a political national convention. How many different committees are possible?

Solution

As the order of the committee does not matter , so we would apply

combination formula:

Combination of 9 things, 3 at a time, 9C3, is 9! / [(9-3)! 3!] = 9×8×7 / (3×2) = 84 committees