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

Step 1: Determine the total hours it takes for 3 pumps to empty the tank.

This is done by multiplying the number of days by the number of hours each pump works per day. So, 2 days * 8 hours/day = 16 hours.

Step 2: Determine the rate at which one pump can empty the tank.

Since 3 pumps can empty the tank in 16 hours, one pump would take 3 times as long, or 16 hours * 3 pumps = 48 hours.

Step 3: Determine how many hours it would take 4 pumps to empty the tank.

Since one pump takes 48 hours to empty the tank, 4 pumps would take 1/4 of that time, or 48 hours / 4 pumps = 12 hours.

Step 4: Determine how many hours per day the 4 pumps must work to empty the tank in 1 day.

Since the 4 pumps can empty the tank in 12 hours, and they need to do this in 1 day, they must work 12 hours in that day.

So, the 4 pumps must work 12 hours a day to empty the tank in 1 day.