Three small pumps and one large pump are filling a tank. Each of the three small pumps works at 2/3rd the rate of the large pump. If all 4 pumps work at the same time, then they should fill the tank in what fraction of time that it would have taken the large pump alone?
Explanation:
Work done by the large pump = 3 units
∴ Work done by the 3 small pumps = 2 × 3 = 6 units
∴ Work done by all 4 pumps together = 9 units
∴Rate of work of the large pumpRate of work of all 4 pumps=39=13
Rate of work is inversely proportional to time taken for completing the work.
∴TIme taken by the large pumpTime taken by all 4 pumps=31
Hence, option (b).
» Your doubt will be displayed only after approval.
Help us build a Free and Comprehensive Preparation portal for various competitive exams by providing us your valuable feedback about Apti4All and how it can be improved.