Gravitation

Two spherical planets P and Q have the same uniform density $\rho$, and masses Mp and $\mathrm{MQ}_{\mathrm{Q}}$ and surface areas A and 4 A respectively. Another spherical planet $R$ also has the same uniform density $\rho$, and its mass is $\mathrm{Mp}+\mathrm{MQ}$. The escape velocities from these planets is