Question

A swimming pool holds 12,500 gallons of water at the start of the day. A valve at the bottom of the pool releases water into a cleaning tank at a constant rate of 20 gallons per hour. A hose is running water into the pool at a constant rate of 60 gallons per hour. On one day, the hose was running for 3 hours, and the valve was left open for 6 hours. How much water is in the pool at the end of the day?

Answer 1

starting with 12,500 gallons, if the hose was running for three hours, 180 gallons would have been added to the pool. 12,500+180=12,680. if the valve was open for six hours, (20x6=120) 120 gallons would have been lost. 12,680-120=12,560. 12,560 gallons of water are in the pool at the end of the day.