Question

There are 720 dishes that need to be rinsed. Brian can rinse them in 72 minutes by himself. It will take his friend Boris 144 minutes to rinse these dishes. How

long will it take them itthey rinse these 720 dishes together?
minutes

Answer 1

It will take both of them 48 minutes to rinse all the dishes.

Explanation:

Brian can do 720/72 = 10 dishes per minute.

Boris can do 720/144 = 5 dishes per minute

Together, they do 15 dishes per minute

720/15 = 48 minutes