- Humber Inc. buys items for $45.25 each. It costs $270.25 to place an order with the supplier. Annual demand is 23380 units, and the annual holding costs are charged at 18%. (a) Find the economic order quantity and the optimal time between orders. The annual number of items demanded D is: E: The fixed cost per order 00 is: [: Enter I in decimal form (Le. 0.03 instead of 3.00%) The annual holding cost rate I is: :] The unit cost of the inventory item 0 is: : Round your answer for Oh to 2 decimals. The cost of holding one item in inventory for one year Ch is: :1