Moment of inertia of the wheel= 0.139 kg m²
Explanation;
diameter of wheel=66.7 cm=0.667 m
radius=d/2 =0.667/2=0.3335 m
The moment of inertia of a wheel is given by
i= m r²
m= mass of the wheel=1.25 kg
r= radius of wheel=0.3335 m
i= 1.25 (0.3335)²
i=0.139 kg m²