A wheel comprises of a ring of radius R and M and three spokes of mass m each moment of inertia of the wheel about its axis is:
M+m4R2
M+mR2
M+3mR2
M+3m2R2
Moment of inertia of the ring is MR2 and that of each spoke is mR23 .
Total moment of inertia MR2+mR23×3=M+mR2