Sand is dropping on a pile that is shaped like a cone with the normal volume for a cone. The radius is growing at a rate of 2 cm per minute. The height is growing at a rate of 1cm per minute. How fast is the volume changing when the radius is 10 cm.

What do you take the derivative of? Before I was trying to take the derivative of the volume and having r be a function of t and h also a function of t... if you could show me the steps it would be a great help!

Thanks!

George