Two Objects, X and Y, Are Held at Rest on a Horizontal

Multiple Choice

Two objects, X and Y, are held at rest on a horizontal frictionless surface and a spring is compressed between them.The mass of X is 2/5 times the mass of Y.Immediately after the spring is released, X has a kinetic energy of 50 J and Y has a kinetic energy of:

A) 20 J
B) 8 J
C) 310 J
D) 125 J
E) 50 J