SOLUTION: Jack usually mows his lawn in 5 hours. Maria can mow the same yard in 3 hours. How long will it take for them to mow the lawn together?

Question 511623: Jack usually mows his lawn in 5 hours. Maria can mow the same yard in 3 hours. How long will it take for them to mow the lawn 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. Maria can mow the same yard in 3 hours. How long will it take for them to mow the lawn together?
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Jack rate = 1/5 job/hr
Maria rate = 1/3 job/hr
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Together rate = 1/x job/hr
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Equation:
rate + rate = together rate
1/5 + 1/3 = 1/x
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Multiply thru by 15x
3x + 5x = 15
8x = 15
x = 15/8 = 1 7/8 hr = 1hr 52.5 minutes (time to do the job together)
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Cheers,
Stan H.
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Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
Let = the time for them
to mow 1 lawn working together
Jack's rate of mowing:
( 1 lawn ) / ( 5 hours )
Maria's rate:
{ 1 lawn ) / ( 3 hours )
Add their rates of working:

Multiply both sides by

This is 1 hour + 7/8 of an hour

It takes them 1 hr and 52.5 min
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