Physics Question about Momentum and Collision?

Two collide head-on on a table. The first ball has a m of 1.2 kg and an initial velocity of 2.7 m/s. The second ball has a m of 1.8 kg and an initial velocity of -2.8 m/s. After the collision, the first ball travels at a velocity of -4.8 m/s. What is the velocity of the second ball after the collision? ume a perfectly elastic collision and no friction between the and the table. Momentum is conserved in this collision.