The densities of two solid spheres A and B of the same radii R vary with radial distance r as $$\rho_A(r) = k \left(\frac{r}{R}\right)$$ and $$\rho_B(r) = k \left(\frac{r}{R}\right)^5,$$ respectively, where k is a constant. The moments of inertia of the individual spheres about axes passing through their centres are $$I_A$$ and $$I_B,$$ respectively. If $$\frac{I_B}{I_A} = \frac{n}{10},$$ the value of n is