Question 1063903
Jen does one-quarter of a job in 3 hours:
If it takes Jen 3 hours to complete 1/4 of the job, that means it would take her 12 hours to complete the entire job.
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If Nicky works 2 hours more than Jen, she can finish one-sixth of the job:
This means Nicky can complete 1/6 of the job in 5 hours.  If it takes Nicky 5 hours to complete 1/6 of the job, that means it would take her 30 hours to complete the entire job.
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Working together:

Jen's rate = 1/12 job per hour
Nicky's rate = 1/30 job per hour
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TIME * RATE = JOB
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TIME * (1/12 + 1/30) = 1
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TIME * (5/60 + 2/60) = 1
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TIME * (7/60) = 1
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TIME = 60/7 hours