Collisions Questions

A ball moving with velocity $2\text{ m/s}$ collides head on with another stationary ball of double the mass. If the coefficient of restitution is $0.5$ then their velocities (in $\text{m/s}$) after collision will be:

Two spheres $A$ and $B$ of masses $m_1$ and $m_2$ respectively collide. $A$ is at rest initially and $B$ is moving with velocity $v$ along x-axis. After collision $B$ has a velocity $v/2$ in a direction perpendicular to the original direction. The mass $A$ moves after collision in the direction:

Two identical balls $A$ and $B$ having velocities of $0.5\text{m/s}$ and $-0.3\text{m/s}$ respectively collide elastically in one dimension. The velocities of $B$ and $A$ after the collision respectively will be: