1. **State the problem:** Jack Williams ordered products with a combined list price of 27393. The vendor offers trade discounts of 20%, 10%, and 10%. The invoice is dated September 4 with terms 3/15, n/30, and a shipping charge of 748.38. We need to find: (a) Total amount of invoice excluding shipping. (b) Final discount date. (c) Net payment date. (d) Amount to pay in full on September 11 including shipping. 2. **Calculate the total amount excluding shipping:** The list price is 27393. Apply successive trade discounts: 20%, then 10%, then 10%. Formula for successive discounts: $$\text{Net Price} = \text{List Price} \times (1 - d_1) \times (1 - d_2) \times (1 - d_3)$$ where $d_1=0.20$, $d_2=0.10$, $d_3=0.10$. Calculate: $$\text{Net Price} = 27393 \times (1 - 0.20) \times (1 - 0.10) \times (1 - 0.10)$$ $$= 27393 \times 0.80 \times 0.90 \times 0.90$$ $$= 27393 \times 0.648$$ $$= 17743.464$$ 3. **Find the final discount date:** Terms 3/15 means a 3% discount if paid within 15 days from invoice date (September 4). Final discount date = September 4 + 15 days = September 19. 4. **Find the net payment date:** Terms n/30 means full payment due within 30 days from invoice date. Net payment date = September 4 + 30 days = October 4. 5. **Calculate amount to pay on September 11 including shipping:** September 11 is within the discount period (before September 19), so 3% discount applies. Discount on net price: $$\text{Discount} = 17743.464 \times 0.03 = 532.30392$$ Amount after discount: $$17743.464 - 532.30392 = 17211.16008$$ Add shipping charge 748.38: $$17211.16008 + 748.38 = 17959.54008$$ Rounded to two decimals: 17959.54 **Final answers:** (a) 17743.46 (b) September 19 (c) October 4 (d) 17959.54