Question

three pumps working 8 hours a day can empty a tank in 2days.How many hours a day must 4 pumps work to empty the tank in 1 day?

Answer 1

Answer:

your answers is

4 pumps will take 4 hours to empty the tank in 1 day.

Answer 2

total time taken to complete the work is 16 hrs as they completed it in 2 days working 8 hrs a day

now if 3 pumps can finish the work in 16 hrs

then they are finishing 1/16th of the work in 1 hour

so three pumps do 1/16th of it

then 1 pump does 1/48th of the work in 1 hr

so 4 pumps would do 1/12th of the work in 1 hr

thus it would take 12 hrs to finish the work if there are 4 pumps