$8.($a$)$ Make a Markov chain model for a rat wandering through the f o$]-$

lowing maze if$,$ at the end of each period, the rat is equally likely

to leave its current room through any of the doorways. $($It never

stay where it is$.)$

I

$1$ A $2$

I$-----<5>--$

$4$ y $3$