I think we have to get e........
Approach condition:
The ball dropped from height h+d
Conserving the energy => 1/2 mu2=mg(d+h)
=> u=√[2g(d+h)]
Separation condition
The ball rises to height h
Conserving energy again => 1/2 mv2=mgh
=>v=√[2gh]
Since floor is at rest
=> e=√[2gh] /√[2g(d+h)]
[I hope u can apply sign convention]
=>e= √h/d+h