Three pipes A, B and C can fill a tank in 6 hours. After working at it together for 2 hours, C is closed and A and B can fill the remaining part in 7 hours.
How many hours will be taken by C alone to fill the tank?
14
Part filled in 2 hours =26=13
Remaining part = (1−13)=23
∴ (A + B)'s 7 hour's work = 23
(A + B)'s 1 hour's work = 221
C's 1 hour's work = [(A + B + C)'s 1 hour's work – (A + B)'s 1 hour's work] =(16−221)=114
∴ C alone can fill the tank in 14 hours.