JEE Advanced Model Paper 3 with solutions for online practice

Two elastic balls of masses M and m(M ≫ m) are placed on top of each other with a small gap between them. The balls are dropped on to the ground with the bottom of the lower ball at height h above the ground. The lower ball has a radius Rand the upperball has negligible dimension. The ball of mass m will bounce above the ground to a height ( 2R + nh) where n is