Question 4

A pen stand made of wood is in the shape of a cuboid with four conical depressions to hold pens. The dimensions of the cuboid are $15\text{ cm}$ by $10\text{ cm}$ by $3.5\text{ cm}$ and the radius of each of the four conical depressions is $0.5\text{ cm}$. Find the volume of the wood in the stand.