Question

Two bodies a and b made of same material have the moment of inertia

Answer 1

they have same moment of inertia if they same mass

Answer 2

Hello.We have to find Moment of inertia of point particle as shape is not mentioned.For a point particle,

I = mr2

By formula we can see that I (Moment of inertia) is directly proportional to m (Mass)

So we can derive a simple relationship i.e. I1*m1 = I2*m2  

It is given that IA : IB = 16:18

So by calculation we get, m1:m2 = 9 : 8