A uniform disc of radius R lies in xy plane with its centre at origin. Its moment of inertia about the axis x=2 R  and y=0  is equal to the moment of inertia about the axis y=d  andz=0 . What is d  equal to?

The axis x=2 R, y=0  is in Z direction as shown in. using theorem of ∥ axes, I1=12m R2+m(2R)2=92m R2The axis y=d, z=0  is shown as dotted line in. Again, using the theorem of parallel axes,I2=14m R2+m d2As I2=I1∴  14m R2+m d2=92m R2md2=(92−14)m R2=174m R2d=172R .