The amount of gasoline remaining in the tank decreases with mileage driven. Identify the independent and dependent quantity in the situation.

amount of miles driven; amount of gasoline used

cost of gasoline; amount of miles driven

amount of gasoline remaining in the tank; mileage driven

mileage driven; amount of gasoline remaining in the tank

The independent quantity in this situation is the mileage driven, and the dependent quantity is the amount of gasoline remaining in the tank.