Question

Three pipes a , b and c can fill a tank in 6 hours , after working it at together for 2 hours , c is closed and a and b can fill the remaining part in 7 hours . How much time will c take alone to fill the tank

Answer 1

ans =14 hours

explanation:

Part filled in 2 hours = 2 = 1

6 3

Remaining part = 1 - 1 = 2 .

3 3

(A + B)'s 7 hour's work = 2

3

(A + B)'s 1 hour's work = 2

21

C's 1 hour's work = { (A + B + C)'s 1 hour's work } - { (A + B)'s 1 hour's work }

= 1 - 2 = 1

6 21 14

hence C alone can fill the tank in 14 hours.