Answer:
Step-by-step explanation:
The journal entries are shown below:
On the books of Tuzun Company:
On June 10
Merchandise Inventory A/c $8,000
 To Accounts payable A/c $8,000
(Being inventory purchased on credit) 
On June 11 
Merchandise inventory A/c Dr $400
 To Cash A/c $400
(Being freight is paid by cash) 
On June 12
Account payable A/c Dr $300
 To Merchandise inventory A/c $300
(Being returned inventory is recorded)
On June 19
Accounts payable A/c Dr $7,700 ($8,000 - $300)
 To Cash A/c $7,546 
 To Merchandise Inventory A/c $154 ($8,000 - $300) × 2% 
(Being due amount is paid and the remaining balance is credited to the cash account)
On the books of Epps Company:
On June 10
Accounts receivable A/c Dr $8,000
 To Service revenue A/c $8,000
(Being service provided is recorded)
Cost of goods sold A/c Dr $4,800
 To Merchandise inventory A/c $4,800
(Being inventory sold at cost)
On June 12
Accounts receivable A/c Dr $300
 To Service revenue A/c $300
(Being returned inventory is recorded)
Cost of goods sold A/c Dr $70
 To Merchandise inventory A/c $70
(Being fair value is recorded)
On June 19
Cash A/c Dr $7,546
Sales discount A/c Dr $156
 To Accounts receivable A/c $7,700
(Being payment is received)