<PRE><B>Question 281481</B>
Mark can paint the fence in 15 minutes and Manny can paint the fence in 30 minutes. If Manny and Mark work together how long will it take to paint the fence?
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Mark rate = 1/15 job/min
Manny rate = 1/30 job/min
Together rate = 1/x job/min
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Equation:
rate + rate = together rate
1/15 + 1/30 = 1/x
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Multiply thru by 30x to get:
2x + x = 30
3x = 30
x = 10 minutes (time to do the job together)
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Cheers,
Stan H.</PRE>