MathDB
a drunkard wandering around 4 pubs

Source: 1995 ITAMO p3

January 28, 2020
combinatorics

Problem Statement

In a town there are four pubs, A,B,C,DA,B,C,D, and any two of them are connected to each other except AA and DD. A drunkard wanders about the pubs starting with AA 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 CC at its fifth drink? (b) Where is the drunkard most likely to be after nn drinks (n>5n > 5)?