A solid toy is in the form of a hemisphere surmounted by a right circular cone. The height of the cone is 2 cm and the diameter of the base is 4 cm. Determine the volume of the toy. If a right circular cylinder circumscribes the toy, find the difference of the volumes of the cylinder and the toy.

Explanation

To solve the problem, we need to find the volume of the solid toy, which consists of a hemisphere and a cone, and then determine the difference between the volume of a circumscribing cylinder and the volume of the toy.

### Step-by-Step Solution

**Step 1: Determine the dimensions of the toy.**
- The diameter of the base of the cone (and the hemisphere) is given as 4 cm.
- Therefore, the radius \( r \) of both the hemisphere and the cone is:
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