Puzzle of the Day : TW Puzzle #29 : Travelling Ant Puzzle

Peter and Cynthia stand at each end of a straight line segment.Peter sends 50 ants towards Cynthia, one after another. Cynthia sends 20 ants towards Peter. All ants travel along the straight line segment.Whenever two ants collide, they simply bounce back and start traveling in the opposite direction.

How many ants reach Peter and how many reach Cynthia?