need help with step by step

Question 2 (9 points) The annual demand, ordering cost, and the inventory carrying cost rate for a certain item are D = 10,000 units, S-$75/order and I=20% of item price. Price is established by the following quantity discount schedule. What should the order quantity be in order to minimize the total annual cost? Quantity 1 to 999 1,000 to 4,999 5,000 and up Price $2.50/unit $2.30/unit $1.85/unit Question 2 (9 points) The annual demand, ordering cost, and the inventory carrying cost rate for a certain item are D = 10,000 units, S-$75/order and I=20% of item price. Price is established by the following quantity discount schedule. What should the order quantity be in order to minimize the total annual cost? Quantity 1 to 999 1,000 to 4,999 5,000 and up Price $2.50/unit $2.30/unit $1.85/unit