Consider a star graph consisting of a central vertex and r rays, with one ray consisting of m vertices and the other 1 all consisting of n vertices. Let P, denote the probability that the leaf on the ray of m vertices is the last leaf visited by a particle that starts at 0 and at each step is equally likely to move to any of its neighbors.

(a) Find P2.

(b) Express P, in terms of P,-1.