Answer:
November 5, 202x, merchandise purchased on account, credit terms 5/10, n/60
Dr Merchandise inventory 11,400
Cr Accounts payable 11,400
November 7, 202x, 40 defective units returned
Dr Accounts payable 480
Cr Merchandise inventory 480
November 15, 202x, paid invoice within discount term
Dr Accounts payable 10,920
Cr Cash 10,374
Cr Purchase discounts 546