Brands A, B and C have consumer loyalties 0.7, 0.8 and 0.9, respectively. This means for example that if a customer buys Brand A on his/her current purchase, then he/she will buy Brand A on the next purchase with probability 0.7. When a customer switches brands, he/she will choose one of the other two brands at random. (a) Find the limit market share of Brand B; (b) Find the expected waiting time for a customer whose last purchase was Brand A to buy Brand C.