<PRE><B>Question 82070</B>
If Sally can paint a house in 4 hours and John can paint the same house in 6 hours, how long will it take to paint the same 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
Multiply thru by 12x to get:
3x + 2x = 12
5x = 12
 x = 2 hrs. (2/5)hr
 x = 2 hrs 24 minutes
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Cheers,
Stan H.</PRE>