1. | 3 pumps, working 8 hours a day, can empty a tank in 2 days. How many hours a day must 4 pumps work to empty the tank in 1 day? |
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Answer: Option C Explanation: Let the required number of working hours per day be x. More pumps, Less working hours per day (Indirect Proportion) Less days, More working hours per day (Indirect Proportion)
4 x 1 x x = 3 x 2 x 8
x = 12. |