The amount of water , in liters, remaining in a tank after minutes of draining is given by the equation . Which of the following describes the meaning of the in this equation?
The initial amount of water, in liters, in the tank
The total time, in minutes, it takes for the tank to drain
The rate, in liters per minute, at which water is draining from the tank
The amount of water, in liters, remaining after 5 minutes
