SOLUTION: One tractor can plow a field in 6 hours. An older model takes twice as long. How many hours will it take if they work together?
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You can put this solution on YOUR website! One tractor can plow a field in 6 hours. An older model takes twice as long. How many hours will it take if they work together?
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Faster rate: 1/6 job/hr
Slower rate: 1/12 job/hr
Together rate: 1/x job/hr
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Equation:
rate + rate = together rate
1/6 + 1/12 = 1/x
Multiply thru by 12x to get:
2x + x = 12
3x = 12
x = 4 hrs (time to do the job together)
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cheers,
Stan H.
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