SOLUTION: Three painters can finish painting a wall in 10 minutes. The first painter can finish a wall in 20 minutes and the second one can do it in 30 minutes. How long would it take the
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Question 171680: Three painters can finish painting a wall in 10 minutes. The first painter can finish a wall in 20 minutes and the second one can do it in 30 minutes. How long would it take the third painter to do the job alone. Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! Three painters can finish painting a wall in 10 minutes. The first painter can finish a wall in 20 minutes and the second one can do it in 30 minutes. How long would it take the third painter to do the job alone.
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1st painter DATA
Time = 20 min/job ; rate = 1/20 job/min
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2nd painter DATA:
Time = 30 min/job ; rate = 1/30 job/min
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3rd painter DATA:
Time = x min/job ; rate = 1/x job/min
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Together DATA:
Time = 10 min/job ;rate = 1/10 job/min
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EQUATION:
rate + rate + rate = together rate
1/20 + 1/30 + 1/x = 1/10
Multiply thru by 60x to get:
3x + 2x + 60 = 6x
x = 60 minutes (time for the 3rd painter to do the job)
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Cheers,
Stan H.
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