rotational mechanics Questions

From a circular ring of mass $M$ and radius $R$ an arc corresponding to a $90^{\circ }$ sector is removed. The moment of inertia of the remaining part of the ring about an axis passing through the centre of the ring and perpendicular to the plane of the ring is $K$ times $M{R}^2$. Then the value of $K$ is:

A uniform rod of length $200\text{cm}$ and mass $500\text{g}$ is balanced on a wedge placed at $40\text{cm}$ mark. A mass of $2\text{kg}$ is suspended from the rod at $20\text{cm}$ and another unknown mass $m$ is suspended from the rod at $160\text{cm}$ mark. Find the value of $m$ such that the rod is in equilibrium. ($g=10{\text{m/s}}^2$)