Judy Jones Purchases Groceries and Pop Exactly Once Each Week $\# 9$

Multiple Choice

Judy Jones purchases groceries and pop exactly once each week on Sunday evenings. She buys either Coke or Pepsi only and switches from Coke to Pepsi and vice-versa somewhat regularly. Her purchasing behavior of these two drinks is modeled as a Markov system. Let the transition matrix be:

If in Week \#7, Judy has purchased Coke, what is the probability that she would purchase Pepsi in Week $\# 9$ ?

A) 0.21
B) 0.39
C) 0.18
D) cannot tell without her purchase behavior in Weeks 1-6