Two particles having masses m and 2m are travelling along x-axis on a smooth surface with velocities u_(1) and u_(2), collide. If their velocities after collision are v_(1) and v_(2) , then the ratio of velocities of their centre of mass before and after impact is

Two particles having masses m and 2m are travelling along x-axis on a

1.	Two particles having masses m and 2m are travelling along x-axis on a smooth surface with velocities u_(1) and u_(2), collide. If their velocities after collision are v_(1) and v_(2) , then the ratio of velocities of their centre of mass before and after impact is
Answer» `2:1` `2:3` `1:1` `1:2` ANSWER :C