To my friend - Aditya KumarDiscrete Mathematics Level 5
Today it's Aditya's Birthday. He invited his friends Surya, Adarsh, Mehul and Rajdeep for party. All five participated in in a game of ball passing, where they pass the ball from one person to another (but not to themselves). If initially the ball was with Aditya, and after seven passes the ball is with Aditya too, how many ways could this game have proceeded?