|
|
Pipes & Cisterns - Quant/Math - CAT 2009
Question 4 the day:
June 9, 2003
The question for the day is from the topic of Pipes & Cisterns.
- Pipe A can fill a tank completely in 5 hours. However, on account of a leak at the bottom of the tank, it takes 3 more hours to fill the tank. How long will the leak take to empty a full tank, when pipe A is shut?
| (1) |
13 hours 20 minutes |
| |
(2) |
7.5 hours |
| (3) |
14 hours 40 minutes |
| |
(4) |
None of these |
Correct Answer - (1)
Solution:
Pipe A can fill a tank in 5 hours.
Therefore, it fills 1/5th of the tank or 20% of the tank in an hour.
On account of a leak at the bottom, it takes 3 more hours to fill the tank. i.e. it takes 8 hours to fill the tank now. Or 1/8th of the tank gets filled in an hour = 12.5% of the tank.
The leak has been responsible for emptying 7.5% of the tank every hour – the difference between the original 20% and the post leak 12.5%.
So, if the leak empties 7.5% of the tank in an hour, it will take 100/7.5 = 13.33 hours = 13 hours and 20 minutes to empty a full tank.
|
|
|
|
