Prepare the necessary journal entries to record the following transactions, assuming Oldman Company uses a perpetual inventory system. (a) Oldman sells $54,000 of merchandise, terms 1/10, n/30. The merchandise cost $30,000. (b) The customer in (a) returned $5,000 of merchandise to Oldman. The merchandise returned cost $3, 500. (c) Oldman received the balance due within the discount period. (Credit account titles are automatically indented when the amount is entered. Do not indent manually.)