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On March 12, Fret Company sold merchandise in the amount of $11,800 to Babson Company, with credit terms of 3/10, n/30. The cost of the items sold is $6,500. Fret uses the perpetual inventory system and the net method of accounting for sales. On March 15, Babson returns some of the merchandise. The selling price of the returned merchandise is $1,000 and the cost of the merchandise returned is $550. The entry or entries that Fret must make on March 15 is (are)