# Can you solve it?#4

**Discrete Mathematics**Level pending

There are four basket-ball players A,B,C,D. Initially, the ball is with A. The ball is always passed from one person to a different person. In how many ways can the ball come back to A after seven passes? (For example A → C → B → D → A → B → C → A and A →D→A→D→C→A→B→Aaretwowaysinwhichtheball can come back to A after seven passes.)