D. Calculate cash discounts and net amounts due. OBJECTIVES 2, 3, 5, 6 19. Corner Grocery received an invoice for $689.30, dated October 8, with terms 2/10, n/30. How much should they pay on October 15? 20. How much should the store pay on October 20? 21. Suppose the invoice above included shipping charges of $32.80 and was paid on October 15. How much does the store pay on this invoice