SOLUTION: Steve Dalton can mow his lawn in 4 hours. His sister Diane can now the same lawn in 3 hours. How many hours will it take them to mow the lawn if they work together?

Question 888409: Steve Dalton can mow his lawn in 4 hours. His sister Diane can now the same lawn in 3 hours. How many hours will it take them to mow the lawn if they work together?
Found 2 solutions by JulietG, richwmiller:
Answer by JulietG(1812) (Show Source): You can put this solution on YOUR website!
It takes 7 man-hours for Steve and Diane to mow 2 lawns, or 3.5 man-hours per lawn. Working together, it will take half that amount of time, or 1.75 man-hours. 1.75 man-hours = 1 hour 45 minutes.
Answer by richwmiller(17219) (Show Source): You can put this solution on YOUR website!

x/4+x/3=1
or
1/4+1/3=1/x
3/12+4/12=1/x
7/12=1/x
12/7=x
1 5/7=x
x=1.714

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