This question doesn't make much sense. If both objects have the same momentum, they will 'bounce off' of one another, if one has more momentum than the other, then both of the objects will go in the direction that that object was travelling but with less momentum and therefore less speed.
If a block was travelling that > way with a momentum of 5kgm/s and another is travelling that < way with a momentum of 20kgm/s then both blocks would travel that < way with a momentum of 15kgm/s because you do the larger momentum - the smaller momentum.
If a block was travelling that > way with a momentum of 10kgm/s and another was travelling that < way with a momentum of 10kgm/s, they would collide and the one going that > way would go < that way with a momentum of 10kgm/s and vice versa as they would pass their momentum to each other so they'd keep the same momentum.
