SOLUTION: It takes Rob 3 hours to do a job. It takes Tim 5 hours to do the same job. If Rob and Tim worked together, how long would it take them? Please advise. Thank you.
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Question 318574: It takes Rob 3 hours to do a job. It takes Tim 5 hours to do the same job. If Rob and Tim worked together, how long would it take them? Please advise. Thank you.
You can put this solution on YOUR website! It takes Rob 3 hours to do a job. It takes Tim 5 hours to do the same job. If Rob and Tim worked together, how long would it take them?
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Let x = time it would take for them to working together
then
x(1/3 + 1/5) = 1
multiplying both sides by 15:
x(5 + 3) = 15
8x = 15
x = 15/8
x = 1.875 hours
or
x = 1 hour and 53 minutes
