The radius of planet is twice the radius of earth. Both have almost...

According to the question R_P=2 R_E, \rho_E=\rho_P Escape velocity of earth $$\begin{aligned}V_E & =\sqrt{\frac{2 G M_E}{R_E}}=\sqrt{\frac{2 G}{R_E}\left(\frac{4}{3} \pi R_E^3 \rho_E\right)}\\ & =R_E \sqrt{\frac{8}{3} \pi G \rho_E} \end{aligned}$$Similarly Escape velocity of planet $$\begin{aligned}V_P & =\sqrt{\frac{2 G M_P}{R_P}}=\sqrt{\frac{2 G}{R_P}\left(\frac{4}{3} \pi R_p{ }^3 \rho_p\right)}\\ & =R_P \sqrt{\frac{8}{3} \pi G \rho_p} \end{aligned}$$from eq. (i) and eq. (ii) $\frac{V_E}{V_P}=\frac{R_E}{R_P} \sqrt{\frac{\rho_E}{\rho_P}}=\frac{R_E}{2 R_E} \sqrt{\frac{\rho_Q}{\rho_E}}=\frac{1}{2} ($given) \Rightarrow V_p=2 V_E