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.