SOLUTION: Marge can paint her house in 12 hours. If John helps her it takes them 9 hours. How long does it take John to paint the house by himself
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Question 96141: Marge can paint her house in 12 hours. If John helps her it takes them 9 hours. How long does it take John to paint the house by himself Answer by checkley71(8403) (Show Source):
You can put this solution on YOUR website! 12j/(12+j)=9 now cross multiply
9(12+j)=12j
108+9j=12j
12j-9j=108
3j=108
j=36 hours for John to paint the house.
proof
12*36/(12+36)9
432/48=9
9=9
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