Unfortunately I suck at simple word problems like this, even though the solution for this problem will probably be very simple, but here it goes:

"If Sally can paint a house in 4 hours, and John can paint the same house in 6 hours, how long will it take for both of them to paint the house together?"

The answer is two hours and twenty four minutes; I just don't know how to get this answer. Please, someone help!!!(Crying)