It takes Sarah 6 hrs longer to paint a room than it takes John. Working together, they can paint the room in 4 hours. How long in hours) would it take Sarah to paint the room alone?
Let John's hourly rate =j Sarah's hourly rate =j + 6 1/j + 1/(j+6) = 1/4, solve for j j = 6 hours - time that John needs to paint the room by himself. 6 + 6 = 12 hours - time that Sarah needs to paint the room by herself.
