SOLUTION: Bob can mow the lawn in 5 hours, and Fred can mow the lawn in 4 hours. How long will it take them to mow the lawn together?

Algebra ->  Equations -> SOLUTION: Bob can mow the lawn in 5 hours, and Fred can mow the lawn in 4 hours. How long will it take them to mow the lawn together?      Log On


   

Question 1104106: Bob can mow the lawn in 5 hours, and Fred can mow the lawn in 4 hours. How long will it take them to mow the lawn together?
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
1%2F%281%2F5%2B1%2F4%29, in hours
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Look at the rate unit for the task: LAWN%2FHOURS

BOB, %281%2F5%29%28LAWN%2FHOURS%29
FRED, %281%2F4%29%28LAWN%2FHOURS%29

When Bob and Fred work on the lawn together, the combined rate is 1%2F5%2B1%2F4, LAWNS PER HOUR.