Question

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. The number of hours taken by C alone to fill the tank is:
A.10
B.12
C.14
D.16

Answer 1

10 I think but I did 't know Right Answer
$10$

Answer 2

Answer:

C. 14

Step-by-step explanation:

All the pipes A, B, C can fill the tank in  6hrs

So (A+B+C)'S 1 hr Work = 1/6

(A+B+C)'S 2 hr Work = 2/6 = 1/3

Remaining Part in tank after C is closed = 1-1/3 = 2/3

So (A+B)'s 7 hr work = 2/3

(A+B)'s 1 hr work = 2/21

C's 1 hr work = (A+B+C)'s 1 hr work - (A+B)'s 1 hr work

                            = 1/6 - 2/21 = 3/42

                            = 1/14

So Time taken by Pipe C alone to fill the tank is 14 hrs.