SOLUTION: "Bob takes 7 hours to mow his lawn. Sally mows the same lawn in 4 hours. How long will it take them together.? What is the formula to solve this question?"

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Question 131043:

"Bob takes 7 hours to mow his lawn. Sally mows the same lawn in 4 hours. How long will it take them together.?
What is the formula to solve this question?"

Answer by checkley71(8403) About Me  (Show Source):
You can put this solution on YOUR website!
THE FORMULA IS:
XY/(X+Y)
7*4/(7+4)
28/11=2.54545 HOURS TO FINISH THE JOB TOGETHER.