UPSEE 2018 Solved Paper

A tennis ball with (small) mass m2, sits on the top of a basket ball with (large) mass m1. The bottom of the basket ball is at a height h above the ground and the bottom of the tennis ball is at a height (h+d) above the ground. The balls are dropped from rest.
Here, all collisions are elastic and m1>>m2. To what approximate height from the ground tennis ball bounce?