7 pumps, working 10 hours a day, can empty a tank in 20 days. How many hours a…
2024
7 pumps, working 10 hours a day, can empty a tank in 20 days. How many hours a day must 5 pumps operate to empty the tank in 14 days?
- A.
20 hours
- B.
18 hours
- C.
16 hours
- D.
14 hours
Attempted by 2 students.
Show answer & explanation
Correct answer: A
Use the work formula: Pumps × Hours/Day × Days = Constant. For the first scenario, 7 pumps × 10 hours × 20 days = 1400 pump-hours. For the second scenario, let H be the hours per day: 5 pumps × H hours × 14 days = 70H pump-hours. Equating the work: 1400 = 70H. Solving for H gives 20 hours per day.