Question

It takes 32 minutes for 3 people to paint 4 walls. How many minutes does it take 4 people to paint 7 walls?

Answer 1

Explanation:

Assuming each person gets the same amount of work done, each wall in the first scenario takes 8 minutes to paint. If 3 people paint 4 walls, then each person is painting 1 1/3 of a wall. We can use that to find out how long it takes one person to paint 1 1/3 walls:

`(8min)/(wall)*(4)/(3)walls=(32)/(3)min`. Interpreting that, it takes each person 10 2/3 minutes to paint 1 1/3 walls.

If 4 people paint 7 walls, that means that each person is painting 7/4 walls, or 1.75 walls each. Using the fact that it takes 10.66666 minutes to paint 1.33333 walls, we can find out how many minutes it will take to paint 1.75 walls:

`(10.6666)/(1.33333)=(x)/(1.75)` Cross multiply to get

18.666655 = 1.3333x so

x = 14.000 minutes