SOLUTION: Bob can do a job in 5 hours while Bill can do the same job in 8. How many hours would it take them, working together, to do this job?

Question 919593: Bob can do a job in 5 hours while Bill can do the same job in 8. How many hours would it take them, working together, to do this job?
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
Bob can do a job in 5 hours while Bill can do the same job in 8. How many hours would it take them, working together, to do this job?
Bob's rate:: 1/5 job/hr
Bill's rate:: 1/8 job/hr
----
together rate:: 1/x job/hr
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Equation:
rate + rate = together rate
1/5 + 1/8 = 1/x
------
8x + 5x = 40
13x = 40
x = 40/13 = 3 1/3 hr (time to do the job together)
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Cheers,
Stan H.
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