There is a 20% chance that any current client of company A will switch to company B this year. There is a 40% chance that any client of company B will switch to company A this year. If these probabilities are stable over the years, and if company A has 400 clients and company B has 300 clients,
(a) How many clients will each company have next year?
(b) How many clients will each company have in two years?