Consider the set-up of the previous problem but now suppose machine 1 is much more important than 2, so the repairman will always service 1 if it is broken.

(a) Formulate aMarkov chain model for the this system with state space f0; 1; 2; 12g where the numbers indicate the machines that are broken at the time.

(b) Suppose that 1 D 1;1 D 2; 2 D 3;2 D 4. Find the stationary distribution.