Tap P and Q fill the tank up to 2 5 the remaining tank will be filled by only tap p Find the time re...........

Quantitative Aptitude (CDS) Pipes&cistern

Tap P and Q fill the tank up to 2 /5, the remaining tank will be filled by only tap p. Find the time required to fill the tank completely. If P fills the tank in 12 hours and Q fills the tank in 10 hours?

11.2 hours

9.2 hours

6 hours

8.4 hours

Explanation:

P and Q together fill the tank
T(1/12 + 1/10) =2/3
T(5+6) /60 =2/5
T=24/11 hours
Remaining tank 3/5 filled by P only
T1(1/12) =3/5
T1=36/5 hours
Total time=24/11 +36/5
=(120+396)/55
=516/55
=9.2 hours