I need help with this troubling question....please~~~

Suppose there are 3 candidates, X,Y, n' Z, for the mayoralty of a town. Each week during the election campaign, candidate X loses 10% of their support to candidate Y, n' keeps the rest. Similarly each week candidate Y loses 30% of their support to candidate Z, n' keeps the rest. Similarly each week candidate Z loses 20% of their support to candidate X, n' keeps the rest. Initially support for candidates X,Y, n' Z is in the ratio of 20:20:60.

(q) Explain why this situation meets the requirements for a Markov process n' find the transition matrix A, as well as the initial state vector v0 for this Markov process.