In Exercise 12, starting from each of the other junctions, what is the expected number of moves

Question:

In Exercise 12, starting from each of the other junctions, what is the expected number of moves until a robot reaches junction 4?
Suppose we want to know the average (or expected) number of steps it will take to go from state i to state j in a Markov chain. It can be shown that the following computation answers this question: Delete the jth row and the jth column of the transition matrix P to get a new matrix Q. (Keep the rows and columns of Q labeled as they were in P.) The expected number of steps from state i to state j is given by the sum of the entries in the column of (I -Q) -1 labeled i.
In Exercise 12
Robots have been programmed to traverse the maze shown in Figure and at each junction randomly choose which way to go.