Inverted Cone

Geometry Level pending

The top of a cone of radius 10 is inverted so that the very top of the cone touches the base. The height of the resulting frustum is 3. The frustum is pictured below.

What is the volume of the space in between the lateral surface of the frustum and the lateral surface of the cone inserted into it?

NOTE: for a right circular cone, $$V=\pi r^2 \frac{h}{3}$$

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