We apply the parallel axis theorem, using the fact that the moment of inertia of a rod (with mass $m$ and radius $r$ ) about an axis through the center of mass and perpendicular to the plane of the rod is $(1/2) m r^2$ . The moment of inertia of the system is:
$\begin{align*}7 \cdot (1/2) m r^2 + 6 \cdot m \left(2r \right)^2 = m r^2 \left(7/2 +24 \right) = \boxed{m r^2 \left(55/2 \rig...$
Therefore, answer (E) is correct.

Solution to 2001 Problem 25