On May 18, an invoice dated May 17 for $4000 less 20% and 15%, terms 5/10 E.O M was received by Aldo Distributors. (a) What is the last day of the discount period? (b) What is the amount due if the invoice is paid within the discount period? (a) The last day of the discount period is Type a whole number) (b) The amount due if the invoice is paid within the discount period is s (Round to the nearest cent as needed.)