Mass of first body = m; Mass of second body = 4m and KE$_1$ = KE$_2$. Linear momentum of a body p=$\sqrt{2mE} \sqrt m .$ Therefore $\frac{p_1}{p_2}=\sqrt{\frac{m_1}{m_2}}=\sqrt{\frac{m}{4m}}=\sqrt{\frac{1}{4}}=\frac{1}{2}$ or $p_1:p_2 = 1: 2.$