Question

Three 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 days?

Answer 1

3 pumps working in 2days =8×2= 16 hr

Means they can empty a tank in 16 hr .

3pumps 1 hr work = 1/16

1pumps 1 hr work =1/3×16

4pumps 1hr work =4×1/3×16= 1/12

Hence they will empty the tank in 1/ 12 hr