The Law of Conservation Problem! (Application)

1.A large superball and a small superball are dropped from the same initial height H. Both balls bounce back up to a height h , which is just a bit less than H. If, however, the small superball is placed immediately above the large superball and both are dropped to the ground simultaneously from height H, the small superball rebounds to a height h␣ >>> H! Explain this in terms of the Conservation Laws.

2. Conservation Laws

3.The small ball lands above the large ball. It ‘meets’ the large ball on its rebound, and so is given energy and
momentum by the large ball before it (the small ball) rebounds off the large ball and reverses its own direction.

I can only solve it partly.. Can someone please explain this and the answer?