Question

Cal is packing his suitcase to go on a trip. He wants to pack 4 pairs of pants chosen from the 8 pairs of pants in his closet and 5 shirts chosen from the 9 shirts in his closet. In how many different ways can this be done?

Answer 1

8820 ways

Explanation:

Given that :

Selecting 4 pairs of pant from 8 available and selecting 5 shirts from 9 available

Using combination :

4 pants from 8 = 8C4

5 shirts from 9 = 9C5

Recall:

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

8C4 * 9C5 = [8! /(8-4)!4!] * [9! /(9-5)!5!]

8C4 * 9C5 = (8! /4!4!) * (9! /4!5!)

8C4 * 9C5 = 70 * 126

8C4 * 9C5 = 8820 ways