inerita? No clue to what to do?

Question

Rotating object consists of two solid spheres with a radius of 0.2 m and a mass of 2
kg each. They are connected by a thin rod, which is 0.8 m long. Calculate moment of
inertia about the axis going through the center of one of the spheres

Answer 1

moment of inertia of a mass point around an axis = Mr²
r is distance between the point and the objects centre

because the axis goes through one spear considering that sphere I = 2/5 Mr²

other sphere behave like a mass point so I =Mr²
whole I =2/5 Mr² + MR ²

R = 0.8 + 0.2 + 0.2 m
R = 1.2 m
so
I = 2/5 * 2 * (0.2)² + 2 (1.2)²
I = 16/500 + 2 * 1.44
I = 0.032 + 2.88
I = 2.912 kg m²

Answer 2

Since the mass is equally distributed around one sphere, it's moments of inertia cancel. All you need to consider is the other.

The center of inertia for the second is 0.1 + 0.8 + 0.1 away from the center of the first.

I (sphere) = 2/5 m r^2 = 2/5 * 2 * 1^2 = 4/5

Answer 3

I think narendrino's correct