They worked for it for 20 15 days and then B left the work. The remaining work has done by A alone in 20 days more. In how many days A alone can finish the work?
2006-12-20 19:43:27 · 4 answers · asked by raj_paragon 1 in Science & Mathematics ➔ Other - Science
your question is not clear if they worked for 20 days or 15 days together....neway i will solve for both
case 1: when they worked together for 15 days
they together finish work in 30 days,
so in 15 days they will do 1/2 work.
rest (1-1/2) =1/2 work will be done by A alone in 20 days.
Thus A can finish the work alone in 40 days.........
case 2: when they worked together for 20 days
they together finish work in 30 days,
so in 20 days they will do 2/3 work.
rest (1-2/3) =1/3 work will be done by A alone in 20 days.
Thus A can finish the work alone in 60 days.........
2006-12-20 19:53:26 · answer #1 · answered by i m gr8 3 · 0⤊ 2⤋
~Depends on whether or not it was a union job and whether or not it was rated, at least partially, as a two man job. If not, it depends on how much OT A wants to put in, and on how many breaks he takes.
Oh, yeah, I almost forgot. If either of them have to tend the taps in your other homework problem, it'll take time away from this job. Even so, either of them will get the job done more quickly than you learn algebra unless you spend less time trying to get people to do your work for you and you actually devote some time to learning how to do your own work.
2006-12-21 03:47:27 · answer #2 · answered by Oscar Himpflewitz 7 · 1⤊ 0⤋
W/(A + B) = 30
W = 30(A + B)
W - 15(A + B) = 20A
W - 15(W/30) = 20A
W/2 = 20A
A = W/40, so it takes A 40 days to do the entire job alone.
2006-12-21 03:59:52 · answer #3 · answered by Helmut 7 · 0⤊ 1⤋
If some of the early work took two men then 'A'Could not do the job alone!
2006-12-21 13:49:55 · answer #4 · answered by Billy Butthead 7 · 0⤊ 0⤋