9. If a sales firm has 200 A customers and 200 B cus- tomers, and each sales call to an A consumer takes 1 hour and each sales call to a B consumer takes 2 hours, the firm expects 75 sales calls per year to A customers and 100 sales calls per year to B cus- tomers. The salespeople spend 20 percent of their time on non-selling tasks and 25 percent of their time traveling from sales call to sales call. How large should the sales force be? [LO 5]