On October 5, Concord Corporation buys merchandise for resale on account from Riverbed Corporation. The selling price of the goods is $5,200, and the cost to Riverbed Company is $2,700. On October 8, Concord returns defective goods with a selling price of $640 and a cost of $230. It is anticipated that these goods can be resold at a discount at some point in the future for at least their cost of $230, if not more. Both companies use a periodic inventory system. Record the transactions on the books of Riverbed Corporation. (Credit account titles are automatically indented when the amount is entered. Do not indent manually. If no entry is required, select "No Entry" for the account titles and enter o for the amounts.) Date Account Titles and Explanation Debit Credit Oct. 5 Accounts Receivable 5,200 Sales 5,200 8 Sales Returns and Allowances 700 Accounts Receivable 700