Kinetic Energy Loss in Head-On Elastic Collision: Mass Ratios

[mangafan]

in a head-on elastic collision between two masses, one of which is stationary, a experimenter would like the incident mass to lose quarter of its kinetic energy in the collision. What must be the ratio of the masses of the two objects for this to be the case?

 

[siddharth]

You need to show some work. What have you attempted?