There appears to be some missing text in the opening sentence of the question.
Assuming it is as follows:
"A golf ball collides elastically with a bowling ball initially at rest and bounces back."
It is given that the golf ball bounces back with tiny loss in its incident speed.
Initial momentum of the system is
Using law of conservation of momentum, we equate (1) with (2). We get
We see that after collision, bowling ball recoils with twice the initial momentum of golf ball.