CA is a strategy consulting firm that divides its consultants into three classes: Associates, Managers and Partners. the firm has been stable in size for the last 40 years. There has been - and are expected to be - 200 Associates, 50 managers and 20 partners in steady state. the work environment at the firm is very competitive. after five years of working as an associate, a consultant goes up or out, that is, becomes a manager or is dismissed from the company. the number of associates dismissed from the company without being promoted to manager is traditionally about 30 per year. similarly, after several more years, a manager either becomes a partner or is dismissed from the company. As a policy, the firm recruits new mba graduates as associates, no hires are made at the manager or partner level. if a manager is promoted to partner, they remain a partner for a 10 year average. On average, how many MBA's does CA need to hire every year to maintain the same number of associates, managers and partners?