Journalize, record, and post when appropriate the following transactions in the general journal (all sales carry terms of 5/10, n/30):

201X

Aug. 16 Sold merchandise on account to Ralph Co., invoice no. 1, $940.

18 Sold merchandise on account to Market Co., invoice no. 2, $1,800.

20 Issued credit memorandum no. 1 to Market Co. for defective merchandise, $720.

Use the following account numbers: Accounts Receivable, 112; Sales, 411;

Sales Returns and Allowances, 412; Sales Discounts, 413.