A solid sphere of mass $M$ and radius $R$ is divided into two unequal parts. The first part has a mass of $\frac{7 \mathrm{M}}{8}$ and is converted into a uniform disc of radius $2 R$. The second part is converted into a uniform solid sphere. Let $\mathrm{l}_1$ be the moment of inertia of the disc about its axis and $\mathrm{I}_2$ be the moment of inertia of the new sphere about its axis. The ratio $I_1 / I_2$ is given by: