SSC Sample Paper Mock Test-15 SSC CGL Tear-II Paper-1

Three pipes A, B, C can fill a tank in 6 h. After working at it together for 2 h, C is closed and A and B can fill the remaining part in 7 h. The number of hours taken by C alone to fill the tank is

A) 10

B) 12

C) 14

D) 16

Correct Answer: C

Solution :

Part filled by (A+ B+ C) in 2 h \[=\left( \frac{1}{6}\times 2 \right)=\frac{1}{3}\]

\[\frac{2}{3}\] part is filled by (A+B) in 7 h

Whole is filled by (A+ B) in \[\left( 7\times \frac{3}{2} \right)\text{h}=\frac{21}{2}\text{h}\]

Part filled by C in 1 h \[=\left( \frac{1}{6}-\frac{2}{21} \right)=\frac{3}{42}=\frac{1}{14}\]

\[\therefore \] C alone can fill it in 14 h.