Solving a Fishy Collision: Velocity After Impact

[HelloMotto]

Homework Statement

A large fish traveling at 2m/s initially swallos at a smaller fish which is initially at rest. The large fish then, travels at a reduced speed. The large fish weighs 3 times heavier than the smaller fish. What is the velocity of the large fish and the small fish after the collision?

I have no clue as to how to figure this out. Shouldn't both fish be traveling at the same speed after the collision?

 

[Doc Al]

Shouldn't both fish be traveling at the same speed after the collision?

Right. It's an example of a completely inelastic "collision". Set initial momentum equal to final momentum.