A recent report determined that although only three percent of drivers on Maryland highways equipped their vehicles with radar detectors, thirty-three percent of all vehicles ticketed for exceeding the speed limit were equipped with them. Clearly, drivers who equip their vehicles with radar detectors are more likely to exceed the speed limit regularly than are drivers who do not.
The conclusion drawn above depends on which of the following assumptions?
Drivers who equip their vehicles with radar detectors are less likely to be ticketed for exceeding the speed limit than are drivers who do not.
Drivers who are ticketed for exceeding the speed limit are more likely to exceed the speed limit regularly than are drivers who are not ticketed.
The number of vehicles that were ticketed for exceeding the speed limit was greater than the number of vehicles that were equipped with radar detectors.
Many of the vehicles that were ticketed for exceeding the speed limit were ticketed more than once in the time period covered by the report.
Drivers on Maryland highways exceeded the speed limit more often than did drivers on other state highways not covered in the report.
装雷达的人/吃罚单的人/经常超速的人是三种。
由文章给的条件只能推断出装雷达的人更容易吃罚单(A-B),但是结论是装雷达的人更经常超速(A-C),所以存在gap:吃罚单的人=经常超速的人(B-C)
A 削弱
Premises:
– Only 3% of drivers on Maryland highways had radar detectors.
– 33% of vehicles that got speeding tickets had radar detectors.
Conclusion:
Drivers with radar detectors are more likely to exceed the speed limit regularly than other drivers.
原文说:因为超速而贴罚单的司机33%装了某设备,结论是:装了某设备的司机更有可能比没有装的司机经常超速。问假设。
B:因为超速而贴罚单的司机更有可能比没有贴罚单的司机经常超速。
33%在这里显然表示的是一个程度,表明“很多”“大多数”。进而此题可以理解为:某类人(装设备的司机)具备某特质(因超速而贴罚单),说某类人更有可能怎么样,其实也就是说具备某特质的人更有可能怎么样,也就是答案B
需要注意的是:先告诉3%的司机装了设备,再给出33%的司机贴罚单,这一点很重要,否则33%就是一个干扰项目,因为33%无法代表大多数司机,无法表示程度,只有在前面有了3%的对比限制之后,此题才能认为B正确。
开罚单=已超速,二者之间没有逻辑缺失。题干前提ticketed与结论的唯一区别在于那个regularly,B选项为ticketed和regularly之间打了个桥
Group A – vehicles that have radar detectors
Group B – vehicles that get speeding tickets/vehicles that were ticketed for speeding
Group C – vehicles that exceed the speed limit
Premises:
– Only 3% of all vehicles are A
– 33% of B are A
Conclusion:
– A are more likely to be C
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可以说是很绕了,考试的时候我大概会紧张到弃权。。。囧
完善一下
【常用套路】题目最后的regularly需要注意。三种人:装雷达的人equipped their vehicles with radar detectors,因超速吃罚单的人 ticketed for exceeding the speed limit,经常超速的人exceed the speed limit regularly。由文章给的条件只能推断出装雷达的人更容易因超速吃罚单(A-B:equipped their vehicles with radar detectors——ticketed for exceeding the speed limit),但是结论是装雷达的人更经常超速(A-C:equip their vehicles with radar detectors——exceed the speed limit regularly),所以存在gap:因超速吃罚单的人=经常超速的人(B-C: ticketed for exceeding the speed limit——exceed the speed limit regularly)。选B
其实这道题是非常经典的一道题,仔细分析有助于摸清逻辑出题的套路。
一开始说3%的车装电子狗,结果开罚单的车有33%都装了电子狗,是想说明装了电子狗和不装电子狗的车【开罚单】的几率不一样,不然开罚单的车应该也只有3%的是装了电子狗的。
题干下一句说,所以装了电子狗和不装电子狗的车【超速】的几率不一样。注意,GMAT的题干是不存在同意替换的!如果变了表达,几乎肯定会在两个表达覆盖的范围不同上出题。
所以显然,我们的正确选项必须将【开罚单】和【超速】的范围聚拢在一起。那就是B选项。
但这道题是可以通过排除法选出来的。A选项和正确答案正好相反。C选项说数量这和题目关注的百分比无关。D选项讲的是所有开罚单的车。如果是装了电子狗的车开罚单的次数不止一次,那这个选项也有说服力,但这里没有对装没装电子狗做任何区分,对解题没有帮助。E选项也同样,Maryland的车整体怎样对
题目最后的regularly需要注意。装雷达的人,吃罚单的人,经常超速的人是三种。由文章给的条件只能推断出装雷达的人更容易吃罚单(A-B),但是结论是装雷达的人更经常超速(A-C),所以存在gap:吃罚单的人=经常超速的人(B-C)。选B (典型的架桥思维)
ticked和exceed speed limit regularly 是否等于? 选项B补充了这个gap,压根跟数字没关系啊迷惑
不对吧,感觉不用算数啊,前提说33%安装雷达的被罚了,结论说安装雷达的更容易超速,那不就是少了个gap(被罚的一定是经常超速的)因为被罚也有可能是偶尔超速被发现了。。数字是不是迷惑的部分啊。。。。
这个题不紧要看懂题目还要算数。
记有雷达为D,无雷达为D*;超速为E,未超速为E*;经常超速为R
根据题干,有:(1)n(D)/N=3%,n(D*)/N=97%,即n(D)>n(D*);(2)n(DE)/n(E)=33%,n(D*E)/n(E)=67%,即n(DE)n(D),与集合E和集合R无关,不选;
D.意思是n(E)的观测值要比实际值还小,无关选项,不选;
E.讨论集合R以外的问题,无关选项,不选。
记有雷达为D,无雷达为D*;超速为E,未超速为E*;经常超速为R
根据题干,有:(1)n(D)/N=3%,n(D*)/N=97%,即n(D)>n(D*);(2)n(DE)/n(E)=33%,n(D*E)/n(E)=67%,即n(DE)>n(D*E).
我们看到,条件是集合D,E之间的关系,要推出集合D,R之间的关系,一定要有集合E,R之间的关系,下面分析选项:
A.用数学语言表示:n(DE)>(E*R),涉及集合E和R的关系,可以直接选(不放心可以继续用集合运算验证,没有问题,直接推出了结论);
C.n(E)>n(D),与集合E和集合R无关,不选;
D.意思是n(E)的观测值要比实际值还小,无关选项,不选;
E.讨论集合R以外的问题,无关选项,不选。
(不好意思,之前打错了符号,这是最终版,抱歉抱歉!)
记有雷达为D,无雷达为D*;超速为E,未超速为E*;经常超速为R
根据题干,有:(1)n(D)/N=3%,n(D*)/N=97%,即n(D)>n(D*);(2)n(DE)/n(E)=33%,n(D*E)/n(E)=67%,即n(DE)>n(D*E).
我们看到,条件是集合D,E之间的关系,要推出集合D,R之间的关系,一定要有集合E,R之间的关系,下面分析选项:
A.用数学语言表示:n(DE)n(E*R),涉及集合E和R的关系,可以直接选(不放心可以继续用集合运算验证,没有问题,直接推出了结论);
C.n(E)>n(D),与集合E和集合R无关,不选;
D.意思是n(E)的观测值要比实际值还小,无关选项,不选;
E.讨论集合R以外的问题,无关选项,不选。
记有雷达为D,无雷达为D*;超速为E,未超速为E*;经常超速为R
根据题干,有:(1)n(D)/N=3%,n(D*)/N=97%,即n(D)>n(D*);(2)n(DE)/n(E)=33%,n(D*E)/n(E)=67%,即n(DE)n(D*R)/n(R),即n(DR)>n(D*R).
我们看到,条件是集合D,E之间的关系,要推出集合D,R之间的关系,一定要有集合E,R之间的关系,下面分析选项:
A.用数学语言表示:n(DE)n(E*R),涉及集合E和R的关系,可以直接选(不放心可以继续用集合运算验证,没有问题,直接推出了结论);
C.n(E)>n(D),与集合E和集合R无关,不选;
D.意思是n(E)的观测值要比实际值还小,无关选项,不选;
E.讨论集合R以外的问题,无关选项,不选。
cr
根据 结论“Clearly, drivers who equip their vehicles with radar detectors are more likely to exceed the speed limit regularly than are drivers who do not.”
很多被ticket的都是equip的,-》得出结论,equip的比不equip的超速更加频繁---注意这里多了频繁一词的定性----也就是结论中出现了regularly,而premise没有---那么这种,正确选项必定是有regularly的---
结论出现而premise没出现,结论没出现而premise出现的词,一般都会出现的正确选项中-----> assumption的题做法
do sth regularly,sth occur regularly,经常做,经常发生,定期发生。如:I go there quite regularly. 我经常去那儿。
The assumption needs to be something that links B to C i.e. that links ‘vehicles that get speeding tickets’
to ‘vehicles that exceed the speed limit’. Option (B) gives us that relation. It says ‘B are more likely to be C’.
premises didn't mention whether those were ticketed exceed speed limit regularly of not, so this regular word or any similar word has to be shown in assumption: only B does so