新东方网>留学>LSAT考试>LSAT辅导>LSAT分析推理>正文

LSAT分析推理之官网样题(四)

2016-05-10 11:48

来源:LSAC

作者:

  新东方网LSAT频道在此与大家分享LSAC官网上公布的LSAT分析推理样题(四),希望对大家备考LSAT分析推理有所帮助。

  Passage for Questions 5 and 6

  From a group of seven people—J, K, L, M, N, P, and Q—exactly four will be selected to attend a diplomat’s retirement dinner. Selection conforms to the following conditions:

  Either J or K must be selected, but J and K cannot both be selected.

  Either N or P must be selected, but N and P cannot both be selected.

  N cannot be selected unless L is selected.

  Q cannot be selected unless K is selected.

  Question 5

  If P is not selected to attend the retirement dinner, then exactly how many different groups of four are there each of which would be an acceptable selection?

  one

  two

  three

  four

  five

  Explanation for Question 5

  This question adds a new supposition to the original set of conditions—“P is not selected to attend the retirement dinner.” The task is to determine all of the different possible selections that are compatible with this new supposition. A compatible solution is one that violates neither the new supposition nor the original conditions.

  Since the second condition states “[e]ither N or P must be selected ...,” we can infer from the new supposition (P is not selected) and the second condition (either N or P, but not both, is selected) that N is selected. And since N is selected, we know from the third condition that L is selected. In other words every acceptable selection must include both L and N.

  We are now in a good position to enumerate the groups of four which would be acceptable selections. The first condition specifies that either J or K, but not both, must be selected. So you need to consider the case where J (but not K) is selected and the case in which K (but not J) is selected. Let’s first consider the case where J (but not K) is selected. In this case, Q is not selected, since the fourth condition tells you that if K is not selected, then Q cannot be selected either. Since exactly four people must be selected, and since P, K, and Q are not selected, M, the only remaining person, must be selected. Since M’s selection does not violate any of the conditions or the new supposition, N, L, J, and M is an acceptable selection; in fact, it is the only acceptable selection when K is not selected. So far we have one acceptable selection, but we must now examine what holds in the case where K is selected.

  Suppose that K is selected. In this case J is not selected, but Q may or may not be selected. If Q is selected, it is part of an acceptable selection—N, L, K, and Q. If Q is not selected, remembering that J and P are also not selected, M must be selected. This gives us our final acceptable selection—N, L, K, and M.

  Thus there are exactly three different groups of four which make up acceptable selections, and (C) is the correct response.

  This was a difficult question, based on the number of test takers who answered it correctly when it appeared on the LSAT.

  Question 6

  There is only one acceptable group of four that can be selected to attend the retirement dinner if which one of the following pairs of people is selected?

  J and L

  K and M

  L and N

  L and Q

  M and Q

  Explanation for Question 6

  The way in which this question is phrased is rather complex, and so it is important to get very clear what exactly is being asked. Unlike other questions which give you a new supposition to consider in conjunction with the original conditions, this question asks you to determine what is needed, in addition to the original conditions, to guarantee that only one group of four is acceptable.

  One way to approach this question is to consider each option individually, and determine for each option whether only one acceptable group of four can be selected when the pair indicated in the option is selected. You may wish to vary the order in which the options are considered according to personal preferences. In the discussion here, we will consider the answer choices in order from (A) through to (E).

  Choice (A): When both J and L are selected, K cannot be selected (first condition). Consequently Q cannot be selected (fourth condition). More than one group of four is acceptable under these circumstances, however: J, L, M, and N may be selected, and J, L, M, and P may be selected.

  Choice (B): When K and M are both selected, J cannot be selected (first condition). Other than that, anyone else could be selected. This leaves more than one acceptable group of four. K, L, M, and N may be selected; K, L, M, and P may be selected; and K, M, P, and Q may be selected.

  Choice (C): When L and N are both selected, P cannot be selected (second condition), but, as in the case of option (B), anyone else can be selected. This leaves more than one acceptable group of four: J, L, M, and N may be selected; K, L, M, and N may be selected; and K, L, N, and Q may be selected.

  Choice (D): When L and Q are both selected, K must be selected (fourth condition). Consequently J cannot be selected (first condition). Either N or P must be selected (second condition), and there is nothing that rules out either N or P from being selected here. So, more than one group of four is acceptable under these circumstances: K, L, N, and Q may be selected, and K, L, P, and Q may be selected.

  Choice (E): When M and Q are both selected, K must be selected (fourth condition), and hence J cannot be selected (first condition). Furthermore, N cannot be selected: if N were selected, then L would also have to be selected (third condition), and this would violate the restriction that exactly four people are to be selected. And since N cannot be selected, P must be selected (second condition). Thus when M and Q are both selected, both K and P must be selected as well, and only one group of four—K, M, P, and Q—is acceptable. (E) is therefore the correct response.

  This was a very difficult question, based on the number of test takers who answered it correctly when it appeared on the LSAT.

报考指南 考试时间 每年在2月、6月、9月或10月、12月安排考试,点击查看具体安排
考试科目 阅读理解、分析推理、逻辑推理及不计分的写作
官网/报名 报名入口
成绩查询
报考指导 考试费用
考场选择
评分标准
成绩要求

  最新热文推荐:

  留学考试2015年终盘点及2016备考规划

  2016年世界大学排名最新整理

  最新留学申请托福成绩要求

  留学生回国生存指南

  2016年新SAT美国首考解析汇总

  2016年ACT考试形势及备考建议

(责任编辑:马荟)

新东方网托福官方微信:新东方托福 (微信号:xdftoefl

最新考试资讯、托福预测、托福解析,请扫一扫二维码,关注我们的官方微信! 

新东方留学考试辅导专区

班级名称 上课地点 上课时间 费用 详细

焦点推荐

版权及免责声明

凡本网注明"稿件来源:新东方"的所有文字、图片和音视频稿件,版权均属新东方教育科技集团(含本网和新东方网) 所有,任何媒体、网站或个人未经本网协议授权不得转载、链接、转贴或以其他任何方式复制、发表。已经本网协议授权的媒体、网站,在下载使用时必须注明"稿件来源:新东方",违者本网将依法追究法律责任。

本网未注明"稿件来源:新东方"的文/图等稿件均为转载稿,本网转载仅基于传递更多信息之目的,并不意味着赞同转载稿的观点或证实其内容的真实性。如其他媒体、网站或个人从本网下载使用,必须保留本网注明的"稿件来源",并自负版权等法律责任。如擅自篡改为"稿件来源:新东方",本网将依法追究法律责任。

如本网转载稿涉及版权等问题,请作者见稿后在两周内速来电与新东方网联系,电话:010-60908555。