Answer:
The moment of inertia for the cylinder is 1600gcm².
Step-by-step explanation:
In a cylinder with mass m, in g, and radius r, in cm, the moment of inertia is given, in gcm² by the following formula:

In this problem, we have that:
solid cylinder with a mass of 100g and a radius of 4.0 cm. This means that
.
So

The moment of inertia for the cylinder is 1600gcm².