Jada walks up to a tank of water that can hold up to 15 gallons. When it is active, a drain empties from the tank at a constant rate. When Jada first sees the tank, it contains 12 gallons of water. Three minutes later, the tank contains 6 gallons of water.
At what rate is the amount of water in the tank changing. Use a signed number. (positive or negative number)
gallons per minute
How many more minutes will it take for the tank to drain completely?
minutes
How many minutes before Jada arrived was the water tank completely full?
minutes