| Pipes P and Q can fill a tank in 10 and 12 h, respectively and C can empty it in 6 h. If all the three are opened at 7 am, at what time will one-fourth of the tank be filled? [SSS (CPO) 2011] |
A) 10 am
B) 10 pm
C) 11 pm
D) 11 am
Correct Answer: B
Solution :
| Given, tank filled by \[P=10\,\,h,\]filled by \[Q=12\,\,h\]and emptied by \[C=6\,\,h\] |
| Part of tank filled in \[1\,\,h\] when all three pipes are opened |
| \[=\frac{1}{10}+\frac{1}{12}-\frac{1}{6}=\frac{6+5-10}{60}=\frac{1}{60}\] |
| Hence, the tank will be filled in \[60\,\,h.\] |
| \[\therefore \]One-fourth of the tank will be filled in\[=\frac{60}{4}=15\,\,h\] |
| i.e. the tank will be filled at 10 pm. |
You need to login to perform this action.
You will be redirected in
3 sec
