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

1. John's purchased merchandise on account for $5,900. Freight charges of $750 were paid in cash.
2. Johns returned some of the merchandise purchased in (1). The cost of the merchandise was $1,050 and Johns account was credited by the supplier.
3. Merchandise costing $3,250 was sold for $6,100 in cash.

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