<p>Two identical spheres each of mass 2kg&nbsp; &nbsp;and radius&nbsp; 50cm are fixed at the ends of a light rod so that the separation between the centers is 150cm . Then, moment of inertia of the system about an axis perpendicular to the rod and passing through its middle point is&nbsp;<span class="equation">\(\frac{x}{20}kgm^2\)</span>&nbsp;, where the value of x is ___________.</p>