SOLUTION: Katrina can mow the lawn in 2 hours. It takes her brother 3 hours to mow the lawn. When they borrow a neighbor's lawn mower and work together, how long does it take them to mow the

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Question 81310: Katrina can mow the lawn in 2 hours. It takes her brother 3 hours to mow the lawn. When they borrow a neighbor's lawn mower and work together, how long does it take them to mow the lawn?
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Katrina can mow the lawn in 2 hours. It takes her brother 3 hours to mow the lawn. When they borrow a neighbor's lawn mower and work together, how long does it take them to mow the lawn?
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Katrina DATA:
Time to mow the lawn = 2 hrs/job ; Rate = 1/2 job/hr
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Brother DATA:
Time to mow the lawn = 3 hrs/job ; Rate = 1/3 job/hr
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Together DATA:
Time to mow the lawn = x hrs/job ; Rate = 1/x job/hr
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EQUATION:
rate + rate = rate together
1/2 + 1/3 = 1/x
3x+2x = 6
5x=6
x=6/5 of an hour or 1 hr and 12 minutes
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Cheers,
Stan H.