Question 440953: Jimmy can wash his car in 30 minutes his son can wash his car in 120 minutes working together his long will it take them to wash the car? Answer by nerdybill(7384) (Show Source):
You can put this solution on YOUR website! Jimmy can wash his car in 30 minutes his son can wash his car in 120 minutes working together his long will it take them to wash the car?
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Let x = time (mins) it takes for both
then
x(1/30 + 1/120) = 1
multiplying both sides by 120:
x(4 + 1) = 120
x(5) = 120
x = 120/5
x = 24 minutes
