A's work = (B + C)'s work ATQ, (A + B)'s can complete the work in 9 hr 36 minutes i.e.
48
5
hrs C can complete the work in 48 hours.
We know that A's efficiency = (B + C)'s efficiency C's efficiency = 1 then, A – B = 1 and A + B = 5 ⇒ A's efficiency = 3 and B's efficiency = 2 Time taken by B is =