SOLUTION: Working alone, John can do a job in 3 days. Harry could do the same job in 5 days. Assuming a day has 8 hours, how many hours will it take them working together to do the job, assu

Question 917443: Working alone, John can do a job in 3 days. Harry could do the same job in 5 days. Assuming a day has 8 hours, how many hours will it take them working together to do the job, assuming their productivity does not change working together.
Answer by ankor@dixie-net.com(22740) (Show Source): You can put this solution on YOUR website!
Working alone, John can do a job in 3 days. Harry could do the same job in 5 days. Assuming a day has 8 hours, how many hours will it take them working together to do the job, assuming their productivity does not change working together.
:
Change the time factor to hrs
then
John: 3*8 = 24 hrs
Harry: 5*8 = 40 hrs
:
Let t = no. of hrs required when working together
Let the completed job = 1
:
Each will do a fraction of the job, the two fractions add up to 1
+ = 1
multiply equation by the least common multiple of 24 and 40; 120
Canceling the denominators results in:
5t + 3t = 120
8t = 120
t = 120/8
t = 15 hrs working together
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