a. Sold merchandise for cash, $12, 150. The cost of merchandise sold was $9,100.

b. Sold merchandise on account, $6,000. The cost of merchandise sold was $4,000.

c. Sold merchandise to customers who used MasterCard and VISA, $30,780. The cost of merchandise sold was $20,000.

d. Sold merchandise to customers to used American Express, $17,650. The cost of merchandise sold was $10,500.

e. Received an invoice from National Credit Co. for $1,900, representing a service free paid for processing MasterCard, VISA, and American Express sales.