Problema Solution
Jane,Paul and Peter can finish painting the fence in 2 hours. If Jane does the job alone she can finish it in 5 hours. If Paul does the job alone he can finish it in 6 hours. How long will it take for Peter to finish the job alone?
Answer provided by our tutors
Let x represent the number of hours that Peter needs to finish the job alone
1/x of the job per hour is Peter's rate, x>0
1/6 of the job per hour is Paul's rate
1/5 of the job per hour is Jane's rate
1/2 of the job per hour is the together rate of Jane,Paul and Peter
1/x + 1/6 + 1/5 = 1/2
........
........
x = 7.5 hr
Peter does the job alone in 7.5 hours.