关于prep的一道数学题~

anita351601

A certain business produced x rakes each month from November through February and shipped x/2 rakes at the beginning of each month from March through October.The bussiness paid no storage costs for the rakes from November through February,but it paid storage costs of 0.10 dollars per rake each month from March through October for the rakes that had not been shipped.Iterms of x,what was the total storage cost,in dollars,that the business paid for the rakes for the 12 months from november through October?

A.0.40X    B.1.20x     C.1.40x  D.1.60x     E.3.20x

答案是C.

为什么呀？我就是想不通~

哪位能帮我解答一下~ 万分感谢！！！

genius_fang

就是说11月到2月，每月生产x个，3月到10月每月用掉0.5x个，然后生产的时候，不需要费用，也就是11~2这四个月不用保管费，但是3~10这8个月，每个月都要按照库存量每个付0.1元，问你这一年一共保管费付了多少？
那么3月份：库存是4x，所以费用0.4x   之后每个月由于ship掉0.5x个，所以费用少0.05x，就是等差数列加一下啦~答案就是1.4x了~~~

anita351601

就是说11月到2月，每月生产x个，3月到10月每月用掉0.5x个，然后生产的时候，不需要费用，也就是11~2这四个月不用保管费，但是3~10这8个月，每个月都要按照库存量每个付0.1元，问你这一年一共保管费付了多少？
那么3月份：库存是4x，所以费用0.4x   之后每个月由于ship掉0.5x个，所以费用少0.05x，就是等差数列加一下啦~答案就是1.4x了~~~

-- by 会员 genius_fang (2009/12/12 16:06:43)

我终于懂啦~ 原来是每月用掉0.5x啦~ 呵呵~ 我题目都没有看懂~ 谢谢哈~