Question 257685: Jack usually mows his lawn in 7 hours. Marilyn can mow the same yard in 5 hours. How much time would it take for them to mow together? Found 2 solutions by dabanfield, Alan3354:Answer by dabanfield(803) (Show Source):
You can put this solution on YOUR website! Jack usually mows his lawn in 7 hours. Marilyn can mow the same yard in 5 hours. How much time would it take for them to mow together?
Jack's mowing rate is 1/7 lawns per hour. Marilyn's rate is 1/5 lawns per hour.
Their combined rate is 1/7 + 1/5.
Let t be the time it takes for the two of them to mow 1 lawn together. Then:
(1/7 + 1/5)*t = 1
12/35 * t = 1
t = 35/12 hours
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