One thing nice about cylinders is that the rate of change of height remains the same because of its straight sides.

Cone volume =

But we are told 2r=h, so sub:

Differentiate w.r.t h:

We are told dh/dt=-80 and h=10.

Therefore, the volume of the cylinder is filling up at a rate of cubic cm per min.

Since the cylinder has a 20 cm radius, it's volume is