一道洛基JJ题……求分析

cvtty

不明白……不理解……实在搞不懂这题的评价……

GWD32-Q8原题
Last August the XT chain of gasoline stations had a temporary sales promotion in effect. In the promotion, any customer who made a purchase of ten or more gallons of gasoline was entitled to a free car wash. For the month of August, XT experienced a ten percent increase in gasoline sales as compared to sales in August the previous year, so evidently the promotion was successful as a means of boosting sales.
In evaluating the argument, it would be most helpful to answer which of the following?


A.  In the areas in which XT’s gasoline stations operate, how did total combined gasoline sales for all gasoline stations last August compare with sales for the previous August?（Answer）
B.  Was the money that XT earned from the increase in gasoline sales enough to offset the cost of providing free car washes during the promotion?
C.  Were there any customers who bought ten or more gallons at an XT gasoline station during the promotion who would have or more gallons at an XT gasoline in lower quantities, but more frequently, if the promotion had not been in effect?
D.  Did XT or any of its gasoline stations have to pay other businesses to provide the car washes that customers were offered in the promotion?
E.  Are XT’s gasoline sales in August usually significantly higher than one twelfth of XT’s annual gasoline sales?

mofei23

XT’s gasoline stations 和all gasoline stations比较。。。如果其他的gasoline stations也增加了销售量，则不能推出the promotion was successful as a means of boosting sales。

buffonjuventus

我做这道题的分析过程：
去年8月同比前年8月销售增长10%，问判断是否是promotion的因素影响的销量的上升。如若要确定promotion的因素，需要排除它因。因为能够影响sales的因素很多。
A，借用楼上的解释：XT’s gasoline stations 和all gasoline stations比较。。。如果其他的gasoline stations也增加了销售量，则不能推出the promotion was successful as a means of boosting sales。
说的细一点呢，就是如果all gasoline stations的8月销量同比都增加了，同时all stations都采取了某种promotion的话，还是能说明promotion是有效的。但是如果all gasoline stations的8月销量同比都增加了，但是只有XT采取了promotion，那么说明promotion是无效的。

还有一种情况，如果XT在去年全年的sales，相比前年全年增长了10%或10%以上，也不能说明promotion是有效的，因为只有8月推出了加10加仑送洗车的服务。所以假如选项中有某个选项是：whether annual sales of last year increased 10% or more comparing with that of the previous year。我个人觉得这个选项也应该是对的。

cvtty

明白了，忽略了ALL这个单词，还以为一家公司在比较，怎么也不理解……
细节没注意……