GMAT逻辑最难？那是因为你不了解

    很多同学在复习GMAT逻辑时总是过于关注题目的内容或者背景知识，甚至还会有同学考前背机经，但是其实GMAT逻辑中有很多题目背景知识相似，但考察点却完全不同。今天小编就这个问题请到了我们的GRE/GMAT——张老师（撒花）为大家讲解“逻辑之变”！

    下面，我们跟随老师一起来看两个类似案例。

    案例一：
    （题源：PREP）
    At present the Hollywood Restaurant has only standard-height tables. However, many customers come to watch the celebrities who frequent the Hollywood, and they would prefer tall tables with stools because such seating would afford a better view of the celebrities. Moreover, diners seated on stools typically do not stay as long as diners seated at standard-height tables. Therefore, if the Hollywood replaced some of its seating with high tables and stools, its profits would increase.
    The argument is vulnerable to criticism on the grounds that it gives reason to believe that it is likely that
    A．some celebrities come to the Hollywood to be seen, and so might choose to sit at the tall tables if they were available
    B．the price of meals ordered by celebrities dining at the Hollywood compensates for the longer time, if any, they spend lingering over their meals
    C．a customer of the Hollywood who would choose to sit at a tall table would be an exception to the generalization about lingering
    D．a restaurant's customers who spend less time at their meals typically order less expensive meals than those who remain at their meals longer
    E．with enough tall tables to accommodate all the Hollywood's customers interested in such seating, there would be no view except of other tall tables
 
    案例二
    （题源：OG）
    Hollywood restaurant is replacing some of its standard tables with tall tables and stools. The restaurant already fills every available seat during its operating hours, and the change in seating arrangements will not result in an increase in the restaurant's seating capacity. Nonetheless, the restaurant's management expects revenue to increase as a result of the seating change without any concurrent change in menu, prices, or operating hours.
Which of the following, if true, provides the best reason for the expectation?
    A. One of the taller tables takes up less floor space than one of the standard tables. 
    B. Diners seated on stools typically do not linger over dinner as long as diners seated at standard tables. 
    C. Since the restaurant will replace only some of its standard tables, it can continue to accommodate customers who do not care for the taller tables.
    D. Few diners are likely to avoid the restaurant because of the new seating arrangement. 
    The standard tables being replaced by tall tables would otherwise have to be replaced with new standard tables at a greater expense. 

    乍看这两道逻辑题背景知识几乎一致，都是关于tables in Hollywood Restaurants，但事实上两题考查的重点却完全不一样。

    一起分析案例

    案例一中的事实信息是 当前Hollywood Restaurants只有正常高度的桌子，但是顾客更喜欢tall tables with stools（高脚椅），因为方便他们看名人，而且坐在长脚椅上用餐的人在饭店停留的时间会比坐在正常椅子上的顾客要短。 推理内容是Hollywood Restaurants如果把当前的桌椅换成tall tables with stools，收益会增加。问题是找该argument的文本逻辑错误，其实也就是找一个信息使得上文的推理不成立。这一道题的解题重点： 在于我们课上讲过的文本逻辑错误的三种形式，这里主要是从“推理过于化”来解题，即找推理内容的反例。选项A和B的描述对象都是celebrities，而我们这里主要是描述看名人的人，对象不一致，故排除；选项D没有专门提及Hollywood Restaurants，也没有涉及到tall tables with stools，故排除；E中的enough不符合题意，题目中只是说换部分普通桌椅，故排除。这里我们要找的重点是换桌椅并不会让饭店的收入增加，选项C指出了这一点：即使按照一般的餐饮惯例，坐高桌椅的人的要留时间短一点，但是这条惯例在来好莱坞这里吃饭的人身上不成立，换言之，换了桌椅并不会增加翻台率，所以收益也不一定会增加，所以选C。

    案例二中的事实信息是 Hollywood restaurant已经把部分的standard tables换成了tall tables and stools，这样的改变并不会使得该饭店客容量增加，同时菜单、价格、营业时间均不变。推理信息是 这样的改变会使得饭店的收入增加。题目是让我们支持文中信息，即涉及到了strengthen的考察点。 看到这里，同学们心中一定有了一个overlapping sound：这两题明明在互相反驳！没错，逻辑知识点千变万化，同样的背景知识可以出现完全相反的考察点。那我们来回忆下strengthen的知识点，strengthen中预判的过程很重要，在这里我们需要找到收益的增加点。上过课的同学应该记得老师课上说过的控制变量法，结合这道题我们来思考下，价格不变的情况下什么时候收入会增加呢？revenue＝顾客数量＊人均消费，在price不变的情况下，收入增加的原因就是顾客数量增加。选项B提到说人们坐在高脚椅吃饭停留的时间会比在正常桌子旁吃饭停留的时间更短，那这意味翻台率会提高，那么顾客总数增加，因此收入亦会有所增长。因此，这道题的正确答案为B。

    在这里，我想给广大GMAT考生一个小建议：GMAT逻辑点一通百通，希望大家在复习的过程中可以跳出题目本身，总结自己的逻辑知识点存在的问题，并找出问题根源，转变错误的做题思路。