Markov chain-Random walk on a circle
a) A particle moves on 3 points situated on a circle. At each step it is equally likely to move one step clockwise or one step counterclockwise. Use a conditioning argument to determine the mean number of steps for the particle to return to its starting position.
b) Now consider a particle moving on N points situated on a circle, with equal probability at each step of moving clockwise. use a Markov-chain argument to determine the mean number of steps for the particle to return to its starting position.