MathDB

In a town there are four pubs,

A,B,C,D

, and any two of them are connected to each other except

A

and

D

. A drunkard wanders about the pubs starting with

A

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

C

at its fifth drink? (b) Where is the drunkard most likely to be after

n

drinks (

n > 5

3