Johns Specialty Store uses a perpetual inventory system. The following are some inventory transactions for the month of May:

1. Johns purchased merchandise on account for $5,100. Freight charges of $350 were paid in cash.
2. Johns returned some of the merchandise purchased in (1). The cost of the merchandise was $650 and Johns account was credited by the supplier.
3. Merchandise costing $2,850 was sold for $5,300 in cash.

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