<PRE><B>Question 200990</B>
If it takes Sally 4 hours to paint a house and John 6 hours to paint the same house, how long does it take them to paint the house together?
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Sally DATA:
time = 4 hrs/job ; rate = 1/4 job/hr
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John DATA:
time = 6 hrs/job ; rate = 1/6 job/hr
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Together DATA:
time = x hrs/job ; rate = 1/x job/hr
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Equation:
rate + rate = together rate
1/4 + 1/6 = 1/x
3x + 2x = 12
5x = 12
x = 12/5 = 2 2/5 hrs
x = 2 hrs and 24 minutes
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Cheers,
Stan H.</PRE>