问题：A manufacturing company uses 25,000 components at an even rate during a year. Each order placed with the supplier of the components is for 2,000 components, which is the economic order quantity. The company holds a buffer inventory of 500 components. The annual cost of holding one component in inventory is $2.
　　What is the total annual cost of holding inventory of the component?
　　$ ________
　　答案：The correct answer is: $3,000
　　Annual holding cost　=  [buffer (safety) inventory + reorder level/2)] x holding cost per unit
　　                                        =  [500 + (2,000/2)] x $2
　　                                        =   $3,000