Each croquet ball in a set has a mass of 0.45

Question

kg. The green ball, traveling at 12.6 m/s,
strikes the blue ball, which is at rest.
Assuming that the balls slide on a friction-
less surface and all collisions are head-on, find
the final speed of the blue ball in each of the
following situations:
b) The green ball continues moving after the
collision at 2.5 m/s in the same direction.
Answer in units of m/s.
c) The green ball continues moving after the
collision at 0.8 m/s in the same direction.
Answer in units of m/s.