LANG'S TEXT VENTURE As he drove home in his red Ford Mustang, Mark Lang reminisced on the success story of his door-to-door accounting text venture. He was still amazed that he could have accumulated such a fortune selling only two books: Financial Accounting for Fun and Profit and The Joy of Managerial Accounting. His conspicuously attired salespeople sporting their characteristic green eyeshades were remarkably adept at marketeering. Indeed, fully 45 percent of his customers bought the financial accounting text, 35 percent bought the managerial accounting text, and 25 percent bought both.

b) What is the probability that no book is sold?