If A and B together can complete a work in 12 days, B and C together in 15 days and C and A together in 20 days, then in how many days can B alone complete the work :
If A and B together can complete a work in 12 days, B and C together in 15 days and C and A together in 20 days, then in how many days can B alone complete the work :
[A]20 days
[B]24 days
[C]25 days
[D]30 days
20 days
(A + B)’s 1 day’s work
(B + C)’s 1 day’s work
(C + A)’s 1 day’s work
On adding all above equations,
2(A + B + C)’s 1 day’s work
∴ (A + B + C)’s 1 day’s work
∴ B’s 1 day’s work
∴ B alone can do the work in 20 days.
Hence option [A] is correct answer.