SOLUTION: Q. Bill and James can do together a piece of work in 30 days. James alone can finish the work in 60 days, both began the work together but Bill left 3 days before the completion of

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Q. Bill and James can do together a piece of work in 30 days. James alone can finish the work in 60 days, both began the work together but Bill left 3 days before the completion of      Log On


   



Question 196608: Q. Bill and James can do together a piece of work in 30 days. James alone can finish the work in 60 days, both began the work together but Bill left 3 days before the completion of the work. how long will it take to finish the work.?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
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Q. Bill and James can do together a piece of work in 30 days.
James alone can finish the work in 60 days, both began the work together
but Bill left 3 days before the completion of the work.
how long will it take to finish the work.?
:
Since working together it takes 30 days, and working alone J can do half of it
30/60 in 30 day; then B's time alone is 60 days also
:
Let t = time required to finish the job
Let the completed job = 1
:
A simple equation
Bill's time + J's time = the completed job
%28t-3%29%2F60 + t%2F60 = 1
Multiply eq by 60
(t-3) + t = 60
:
2t - 3 = 60
:
2t = 63
:
t = 63%2F2
t = 31.5 days to do the job