Amazon.com sells two tapes: Celebration of Song I and Celebration of Song II. Suppose two types of customers visit Amazon.com: A and B. There are 10 A customers and 15 B customers. A customers are willing to pay $15 for Celebration of Song I and $3 for Celebration of Song II. Type B customers are willing to pay $12 for Celebration of Song I and $8 for Celebration of Song II. Assume Amazon.com's marginal costs for Celebration of Song I and Celebration of Song II are constant at $2 (for each) and there are no fixed costs.

Type A (10) Type B (15) Marginal Cost Celebration of 15 12 N Song I Celebration of 2 Song II TOTAL 18 20 A