SOLUTION: Jane, Paul, and Peter can finish painting the fence in two 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 9 hours. H

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: Jane, Paul, and Peter can finish painting the fence in two 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 9 hours. H      Log On


   



Question 1154079: Jane, Paul, and Peter can finish painting the fence in two 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 9 hours. How long will it take for Peter to finish the job alone?
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!

Jane, Paul, and Peter can finish painting the fence in two hours.
All the three can do 1/2 the job in 1 hour
Jane does the job alone can finish it in 5 hours.
she can do 1/5 of the job in 1 hour

Paul does the job alone can finish it in 9 hours.
He can do 1/9 of the job in 1 hour
Let Peter take x hours to do the job alone
So he does 1/x of the job in 1 hour
1/5 + 1/9+1/x = 1/2
1/x = 1/2 - (1/5 +1/9)
1/x = 1/2 - 14/45
1/x = (45-28)/90
1/x = 17/90
x = 90/17
Peter can do the job alone in 5.3 hours