Question

Three solid spheres each of mass m and diameter d are stuck together such that the lines connecting the centres form an equilateral triangle of side of length d. The ratio I₀/I_A of moment of inertia I₀ of the system about an axis passing the centroid and about center of any of the spheres I_A and perpendicular to the plane of the triangle is :

(1) 13/23

(2) 15/13 

(3) 23/13

(4) 13/15

Answer 1

Answer is (1) 13/23

From parallel axis theorem

Answer 2

Answer is (1) 13/23