future population distribution

Each American family is classified as living in an urban, rural, or suburban location. During a given year, 15% of all urban families move to a suburban location, and 5% move to a rural location; also, 6% of all suburban families move to an urban location, and 4% move to a rural location; finally, 4% of all rural families move to an urban location, and 6% move to a suburban location.

a If a family now lives in an urban location, what is the probability that it will live in an urban area two years from now? A suburban area? A rural area?

b Suppose that at present, 40% of all families live in an urban area, 35% live in a suburban area, and 25% live in a rural area. Two years from now, what percentage of American families will live in an urban area?

c What problems might occur if this model were used to predict the future population distribution of the United States?