1.【答案】A。
解析：
没有折扣：Total cost=Purchase cost+Ordering cost+Holding cost
=18×2,000 + D/Q ×Co + Q/2 ×Ch
=36,000+2,000/400×16+400/2×0.4
=36,160
有2%折扣：Total cost=Purchase cost+Ordering cost+Holding cost
=18×2,000×98% + D/Q ×Co + Q/2 ×Ch
=36,000×98%+2,000/500 ×16+500/2 × 0.4×98%
=35,442
因此当订购数量为500时，总成本最低为$35,442。
知识点：EOQ (with bulk discount) (Chapter 6 Accounting for material)
2.【答案】D。
解析：LIFO: 后进来的存货先卖出
| 18/7 | Closing inventory | 3,000 units for $6,000 |
| 31/7 | Closing inventory | 3,000 units for $6,000 500 units for $1,200 |
| 8/8 | Closing inventory | 2,000 units for $4,000 |
知识点：Inventory valuation (FIFO, LIFO,AVCO) (Chapter 6 Accounting for material)
