A conical tank with vertex down is 10 ft across the top and 12 ft deep. If water is flowing into the tank at a rate of 10 cubic feet per minute, find the rate of change of the depth of the water when the water is 8 ft deep.

A conical tank with vertex down is 10 ft across the top and 12 ft deep. If water is flowing into the tank at a rate of 10 cubic feet per minute, find the rate of change of the depth of the water when the water is 8 ft deep