a pair of identical pucks move towards either other on a frictionless surface with equal speeds, the pucks move apart after colliding. during interaction 3/4 of energy is lost. what is the ratio (momentum of before collision)/(momentum of after the collision)?

Answer 1

One.
If there are no external forces on the two puck system, there is no change in the total momentum. (Even if it approaches 0/0 )