A tank has leakage in its bottom it drains the water of tank in 14 hours Two tap A and B can fill th...........

Quantitative Aptitude (CDS) Pipes&cistern

A tank has leakage in its bottom, it drains the water of tank in 14 hours. Two tap A and B can fill the tank in 7 and 13 hours. If tank A and B fill the tank together up to 2/5 of the tank. The remaining tank was filled only by tap B. Find the total time taken to fill the tank?

27.4 hours

22 hours

30.2 hours

25.21 hours

Explanation:

Let up to 2/5 it fill in t time
t(1/7 + 1/13 -1/14) =2/5
t(26+14-13) /182 =2/5
t(27/182)=2/5
t=364/135
remaining tank filled by B
t1(1/13 -1/14) =3/5
t1 =546/5
Total time =t+t1
=546/5 + 364/135
=580/23 hours
=25.21 hours