Question 1154079

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