<PRE><B>Question 190419</B>
If Sally can paint a house in 4 hours, and John can paint the same house in 6 hour, how long will it take for both of 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
x = 12/5 = 2.4 hrs (time for them to do the job together)
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Cheers,
Stan H.
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