Can someone help me with this AP calc problem?

6. Water is owing at the rate of 50 m3/min into a holding tank shaped like an cone, sitting vertex down. The tank's base diameter is 40 m and a height of 10 m. A. Write an expression for the rate of change of the water level with respect to time, in terms ofh (the water's height in the tank). B. Assume that, at t = U, the tank of water is empty. Find the water Eevel, h, as a function of the time t. C. What is the rate of change of the radius of the cone with respect to time when the water is 8 meters deep