a drunkard wandering around 4 pubs
Source: 1995 ITAMO p3
January 28, 2020
combinatorics
Problem Statement
In a town there are four pubs, , and any two of them are connected to each other except and . A drunkard wanders about the pubs starting with and, after having a drink, goes to any of the pubs directly connected, with equal probability.
(a) What is the probability that the drunkard is at at its fifth drink?
(b) Where is the drunkard most likely to be after drinks ()?