Miscellaneous Question 41
- Two pipes $A$ and $B$ can fill a cistern in 54 minutes and 45 minutes respectively. Both pipes are opened. The cistern will be filled in just half an hour, if pipe $B$ is turned off after
(1) 5 minutes
(2) 9 minutes
(3) 10 minutes
(4) 15 minutes
(5) 20 minutes
(IDBI Bank PO Exam 29.04.2018)
Show Answer
Correct Answer: 41. (5)
Solution: 41. (5) Pipe A works for 30 minutes
$\therefore$ Part of cistern filled by it in 30 minutes
$=\frac{30}{54}=\frac{5}{9}$
Remaining part
$=1-\frac{5}{9}=\frac{4}{9}$
This part is filled by pipe B.
$\therefore$ Required time
$=\frac{4}{9} \times 45=20$ minutes
BETA
