DART GAME

You are throwing darts at dartboard having 20 segments. Your first dart lands randomly at one of the segments. After that your each dart randomly lands at a segment adjacent (left or right) to your previous segment. The game finishes after all the segments have been landed and you record the number of darts thrown.

If you play this game many times, what is the average number of darts thrown at the dartboard?

Popularity: 79.2 %     Difficulty: 50.0 %