feifei逻辑-29 题目第一句话是什么意思啊？

brucechung2011

29. The price of a full-fare coach ticket from Toronto to Dallas
on Breezeway Airlines is the same today as it was a year ago, if inflation is taken into account by calculating prices in constant dollars. However, today 90 percent of the Toronto-to-Dallas coach tickets that Breezeway sells are discount tickets and only 10 percent are full-fare tickets, whereas a year ago half were discount tickets and half were full-fare tickets. Therefore, on average, people pay less today in constant dollars for a Breezeway Toronto-to-Dallas coach ticket than they did a year ago.


Which one of the following, if assumed, would allow the conclusion above to be properly drawn?



(A) A Toronto-to-Dallas full-fare coach ticket on Breezeway Airlines provides ticket-holders with a lower level of service today than such a ticket provided a year ago.

(B) A Toronto-to-Dallas discount coach ticket on Breezeway Airlines costs about the same in constant dollars as they did a year ago.

(C) All full-fare coach tickets on Breezeway Airlines cost the same in constant dollars as they did a year ago.

(D) The average number of coach passengers per flight that Breezeway Airlines carries from Toronto to Dallas
today is higher than the average number per flight a year ago.
(E) The criteria that Breezeway Airlines uses for permitting passengers to buy discount coach tickets on the Toronto-to-Dallas route are different today than they were a year ago.

答案是B。不理解的是，题目里第一句话说，今年的价格和去年的价格考虑了通货膨胀以后是一样的，那么就是说实际上的数额是不一样的吗？然后后面又一直说constant price什么的，然后我就晕了。。。。。求助啊~~~~麻烦帮我理下思路，谢谢~~~~~

dongstar

原来如此，我懂了。感谢楼上！！！

swlfxer

constant dollars是和current dollars相对应的，要考虑到cpi的因素
比如说1990年的10元钱和2009年的10元钱的购买力是不一样的，1990年current dollars是10元，而2009年的current dollars是10元，但是相对于1990年，2009年的constant dollars就可能是1元了

dongstar

想再追问一下,constant dollars 到底是什么概念？我只能理解表面的字义，但体会不了他到底起什么作用？请XDJM解答。多谢。

brucechung2011

讲得好清楚啊~~~太感谢了~~~

zhangluE

今年＝９０％（打折１）＋１０％（全价１）
去年＝５０％（打折２）＋５０％（全价２）
因为人们ＰＡＹ得更少，所以
今年＜去年
因为人们是用ＣＤ付得，因此全价１＝全价２（第一句话得来）
式子就变成了
９０％（折１）＜５０％（折２）＋４０（全２）

加入Ｂ，在ＣＤ情况下折１＝折２，那么
４０％（折２）＜４０（全２），全价肯定高于打折得嘛，正确

还有就是，我把这类题称为双因素题，就是有两个因素

比如文中说得全价和打折，即然文中很明确告诉了全价关系，那么答案很可能锁定在打折关系上

类似的还有供给＋需求，收入＋物价