Superior Co., a furniture wholesaler, sells merchandise to Beta Co. on account, $11,500, terms 2/15, n/30. The cost of the merchandise sold is $6,900. Superior Co. issues a credit memorandum for $900 for merchandise returned and subsequently receives the amount due within the discount period. The cost of the merchandise returned is $540. Journalize Superior Co.'s entries for

(a) The sale, including the cost of the merchandise sold,

(b) The credit memorandum, including the cost of the returned merchandise, and

(c) The receipt of the check for the amount due from Beta Co.