From a disc of radius `r_(1)`, a concentric disc of radius `r_(2)` is removed . The mass of the remaining portion is `m`. Find the `M.I.` of the remaining about an axis passing through the center of mass and perpendicular to the plane.

Explanation

To find the moment of inertia (M.I.) of the remaining portion of the disc about an axis passing through the center of mass and perpendicular to the plane, we can follow these steps:

### Step 1: Define the Masses
Let:
- \( m_A \) = mass of the original disc of radius \( r_1 \)
- \( m_B \) = mass of the removed concentric disc of radius \( r_2 \)
- \( m \) = mass of the remaining portion, which is given.

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