Refer to the transactions in E6–9.
In E6–9, Littleton Books has the following transactions during May.
May 2 Purchases books on account from Readers Wholesale for $3,300, terms 1/10, n/30.
May 3 Pays freight costs of $200 on books purchased from Readers.
May 5 Returns books with a cost of $400 to Readers because part of the order is incorrect.
May 10 Pays the full amount due to Readers.
May 30 Sells all books purchased on May 2 (less those returned on May 5) for $4,000 on account.

Required:
1. Record the transactions of Littleton Books, assuming the company uses a periodic inventory system.
2. Record the period-end adjustment to cost of goods sold on May 31, assuming the company has no beginning or ending inventory.