Got too much work on at the moment, so am having a break from RHP for at least the next few months.
Since this is the only forum I have really posted in I thought I'd say bye and leave you with a couple of (hard) puzzles!!
1) A knight starts at the corner of a chessboard, and at each time t = 1, 2, 3, 4, ... it moves once, with all possible moves equally likely. Let T be the first time the knight returns to its starting corner. What is the expected value of T?
2) A monkey is typing on a typewriter, with each letter A, B, C, ... , Z equally likely. How long before you expect to see the sequence ABRACADABRA?