Answer:
1. There was a purchase of Inventory on account of goods worth $20,580. This figure was debited to the Inventory account and credited to the Accounts Payable.
2. These were the shipping/freight costs. The $300 was debited to the Inventory as a Carriage inwards and credited to the Cash account.
3. The Creditor/ Payable allowed the company to return $3,920 worth of goods. This was credited from the Inventory account and debited to the Payable account.
4. Paid the Account Payable the remaining balance of $16,660 to settle to account. Balance was credited from the Cash account and debited to the Accounts Payable account.