SOLUTION: Bret can plow his driveway in eight hours, his neighbor can plow his driveway in 12 hours, how long will it take if they do it together?

Question 473474: Bret can plow his driveway in eight hours, his neighbor can plow his driveway in 12 hours, how long will it take if they do it together?
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
Bret can plow his driveway in eight hours, his neighbor can plow his driveway in 12 hours, how long will it take if they do it together?
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Bret rate: 1/8 job/hr
Neighbor rate: 1/12 job/hr
Together rate: 1/x job/hr
--------------------------------
Equation:
rate + rate = together rate
1/8 + 1/12 = 1/x
-----------------------
(8+12)/(8*12) = 1/x
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20x = 96
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x = 4.8 hr. = 4hr 48minutes (for them to do the job together)
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Cheers,
Stan H.
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