Question

It takes 36 minutes for 7 people to paint 4 walls. How many minutes dose it take for 9 people to paint 7 walls?

Answer 1

4 walls need 262 people/minutes (7)(36)
1 wall takes 63 people/minutes (262/4)
7 walls need 441 people/minutes (63)(7)
9 people could do that in 49 minutes (441/9)