Don L. answered • 10/21/16

Tutor

5
(12)
Fifteen years teaching and tutoring basic math skills and algebra

Hi Missy, with these types of problems, the way to solve them is to look at how much work they can do in one hour.

John: In one hour, he can do 1 / 3 of the work.

Jim: In one hour, he can to 1 / 5 of the work.

Together: In one hour, they can do 1 / x of the work.

Equation:

1 / 3 + 1 / 5 = 1 / x

To clear the fractions, multiply the entire equation by 15x:

15x * (1 / 3 + 1 / 5 = 1 / x)

5x + 3x = 15

8x = 15

Divide both sides by 8:

x = 15 / 8

John and Jim working together can wax the car in 15 / 8 hours or 1 and 7/8 hours.

Questions?