SOLUTION: John can finish a job in 5 hours. Steve can finish the same job in 4 hours. After working together for 1 hour, steve leaves. How long will it take John to complete the job?

Algebra ->  Rate-of-work-word-problems -> SOLUTION: John can finish a job in 5 hours. Steve can finish the same job in 4 hours. After working together for 1 hour, steve leaves. How long will it take John to complete the job?      Log On


   

Question 811036: John can finish a job in 5 hours. Steve can finish the same job in 4 hours. After working together for 1 hour, steve leaves. How long will it take John to complete the job?
Found 2 solutions by richwmiller, Bastian21:
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
1/5+1/4=4/20+5/20=9/20
20/20-9/20=11/20
x/5=11/20
55/20=x
11/4=2.75 hours

Answer by Bastian21(2) About Me  (Show Source):
You can put this solution on YOUR website!
John time is 5 hours = 1/5
Steve time is 4 hours = 1/4
LCM is 20. (5 x 4 = 20)
Therefore, 4/20 + 5/20= 9/20
20/20 - 9/20 = 11/20
x/5= 11/20
Cross Multiplying
20x=55
Therefore x = 55/20
Time John took to complete the job is = 2.75 hrs