How to Approach a Conservation of Linear Momentum Problem?

[phy journey]

Homework Statement

a 50kg man is standing at one end of a 25m long boat.if he starts running towards the other end,he attains a velocity of 2m/s on reaching the other end.if the mass of the boat is 200kg,what is the velocity of the boat?{can someone give me a hint as to how to approach such kind of problems}

Homework Equations

The Attempt at a Solution

 

[bp_psy]

Start by writing an equation involving the momentum of the man and of the boat before and after he runs the 25m distance.