Question: Let Xn be the number of days since David last shaved, calculated at 7:30 a.m. when he is trying to decide if he wants to shave today. Suppose that Xn is a Markov chain with transition matrix
In words, if he last shaved k days ago, he will not shave with probability 1/(k+1). However, when he has not shaved for 4 days his mother orders him to shave, and he does so with probability 1.
(a) What is the long-run fraction of time David shaves?
(b) Does the stationary distribution for this chain satisfy the detailed balance condition?