Can someone please explain to me why this would be considered incorrect?

Prepare journal entries to record each of the merchandising transactions assuming that the company records purchases using the net method and a perpetual inventory system. November 5 Purchased 1,400 units of product at a cost of $40 per unit. Terms of the sale are 5/10, n/60; the invoice is dated November 5. November 7 Returned 25 defective units from the November 5 purchase and received full credit. November 15 Paid the amount due from the November 5 purchase, minus the return on November 7