John's Specialty Store uses a perpetual inventory system. The following are some inventory transactions for the month of May 2011:

1. John's purchased merchandise on account for $5,000. Freight charges of $300 were paid in cash.
2. John's returned some of the merchandise purchased in (1). The cost of the merchandise was $600 and John's account was credited by the supplier.
3. Merchandise costing $2,800 was sold for $5,200 in cash.

Required:
Prepare the necessary journal entries to record these transactions.