If v(x) represents the volume of water, in cubic inches, in a tank when the height of the water is x inches, give a practical interpretation of (v^−1)(20).

1) the volume of the water in the tank, in cubic inches, after 20 minutes.
2) the volume of the water in the tank, in cubic inches, when the height is 20 inches.
3) the height of the water in the tank is 20 inches.
4) the height of the water in the tank, in inches, when the volume is 20 cubic inches.
5)the volume of the water in the tank is 20 cubic inches.