Question

It takes Nate five hours to paint a wall, and it takes Jill seven hours to paint the same wall. About how many hours will it will take if Nate and Jill work together to paint the wall?

Answer 1

Let's use the relation:


`\mathsf{(1)/(x) = (1)/(5) + (1)/(7)}\\ \\ \\ \mathsf{(1)/(x) = (7+5)/(35)}\\ \\ \\ \mathsf{(1)/(x) = (12)/(35)}\\ \\ \\ \mathsf{x = (35)/(12)}\\ \\ \\ \boxed{\mathsf{x\approx 2.92 \ h}}`

It would take about 3 hours to complete the work.