SOLUTION: Working alone John can pain a house in 7 hours. If Joe and John paint it together they can finish it in 3 hours. How long does it take Joe to pain the house?

Question 361445: Working alone John can pain a house in 7 hours. If Joe and John paint it together they can finish it in 3 hours.
How long does it take Joe to pain the house?
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
Working alone John can paint a house in 7 hours. If Joe and John paint it together they can finish it in 3 hours. h
How long does it take Joe to paint the house?
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John rate = 1/7 job/hr
together rate = 1/3 job/hr
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Joe rate = 1/x job/hr
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Equation:
rate + rate = together rate
1/7 + 1/x = 1/3
3x + 21 = 7x
4x = 21
x = 21/4 = 5 1/4 hrs (Joe's time to paint the house alone)
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Cheers,
Stan H.
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