Doug can paint the living room in 4 hours. it would take elaine 6 hours to paint the same room. how long would it take doug and elaine, working together, to paint the living room?

2.4 hours

You can get this by setting up the equation:

x/4 + x/6 = 1

Where x is equal to the amount of hours spent working. In this equation x/4 would be Doug. In 4 hours he would paint on room. x/6 would be Elaine. When you add them together using common denominators, you can find x.