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