Why does a solid sphere have smaller moment of inertia than a hollow cylinder of same mass and radius, about an axis passing through their axes of symmentry ?

Explanation

Moment of inertia of a body is given by `I= sum m_(i)r_(i)^(2)`. In case of hollow cylinder all mass lies at a distance R from the axis of symmetry but in case of a solid sphere, most of the mass lies at a smaller distance than R. The distance of all the particles of a hollow cylinder from the axis of rotation is same, whereas in case of a solid sphere the perpendicular distance of the points from the axis of rotation are different