A water tank fills through two pipes. Water flows in
through one pipe at a rate of 25,000 gallons per hour
and in through the other pipe at a rate of 45,000
gallons per hour. Water leaves the system at a rate of
60,000 gallons per hour.
There are 3 of these tanks, and each tank holds
1 million gallons. Each tank is half full. Water is
entering and leaving a tank at the maximum
amounts. Determine the number of hours, x, it will
take to fill all 3 tanks one at a time.