A Textbook Publisher Is in Monopolistic Competition

Multiple Choice

A textbook publisher is in monopolistic competition. The firm can sell no books at $100 a book, but for each $10 cut in price, the quantity of books it can sell increases by 20 books a day. The firm's average variable cost and marginal cost is a constant $20 per book. What is the publisher's profit-maximizing price?

A) $40
B) $50
C) $60
D) $70