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A tank is usually filled in 18 hours. But because of a leak in it’s bottom, it takes another 6 hours to fill. How much time will it take to the leak to empty the full tank?
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- 72
- 74
- 75
- 76
- 72
Correct Option: A
Let us consider the case when there is no leak –
| Then in one hour, work done = | ||
| 18 |
| and in 6 hours = | = | ||
| 18 | 3 |
This means 1/3 rd of the tank is emptied because of the leakage in 18 + 6 = 24 hours.
So, 1/3 rd is emptied in 24 hours, full tank would be emptied in 24 × 3 = 72 hours.
Second method to solve this question :
Using formula directly, we get
| Time required by leakage to empty the full tank = | |
| a - b |
Here, a = 18, b = 24
| Hence, t = | = 72 hours | |
| 24 - 18 |
