SOLUTION: Jack usually mows his lawn in 5 hours, Marilyn can mow the same lawn in 4 hours. How much time would it take for them to mow the lawn together.
They could mow the lawn in _?_ h
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They could mow the lawn in _?_ h
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Question 347781: Jack usually mows his lawn in 5 hours, Marilyn can mow the same lawn in 4 hours. How much time would it take for them to mow the lawn together.
They could mow the lawn in _?_ hours if they worked together. Found 2 solutions by stanbon, josmiceli:Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! Jack usually mows his lawn in 5 hours, Marilyn can mow the same lawn in 4 hours. How much time would it take for them to mow the lawn together.
They could mow the lawn in _?_ hours if they worked together.
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Jack rate: 1/5 job/hr
Marilyn rate: 1/4 job/hr
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Together rate: 1/x job/hr
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Equation:
rate + rate = together rate
1/5 + 1/4 = 1/x
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Multiply thru 20x to get:
4x + 5x = 20
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9x = 20
x = 20/9
x = 2 2/9 hrs (time to do the job together)
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Cheers,
Stan H.
You can put this solution on YOUR website! Add their rates of mowing to get the rate mowing together
Jack's rate: 1 lawn/5 hrs
Marilyn's rate: 1 lawn/4 hrs
Rate working together = 1 lawn/x hrs
multiply both sides by hrs
This is about 2 hrs and 13 min
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