A solid sphere (A) of mass 5 m and a spherical shell (B) of mass m , both having same radius, are placed on a rough surface. When a force of same magnitude is applied tangentially at the highest points of A and B, they start rolling without slipping with an acceleration of $\mathrm{a}_{\mathrm{A}}$ and $\mathrm{a}_{\mathrm{B}}$, respectively. The ratio of $\mathrm{a}_{\mathrm{A}}$ and $\mathrm{a}_{\mathrm{B}}$ is $\_\_\_\_$ .