gwd18-15
Fact: Asthma, a bronchial condition, is much less common ailment than hay fever, an allergic inflammation of the nasal passages
Fact:Over 95 percent of people who have asthma also suffer from hay fever.
If the information given as facts above is true, which of the following must also be true?
A.Hay fever is a prerequisite for the development of asthma.
B.Asthma is a prerequisite for the development of hay fever.
C. Those who have neither hay fever nor asthma comprise less than 5 percent of the total population.
D. The number of people who have both of these ailments is greater than the number of people who have only one of them.
E.The percentage of people suffering from hay fever who also have asthma is lower than 95 percent.
参考答案是E，我觉得应该是在A B里选一个吧，我选A
如果Hay fever is a prerequisite for the development of asthma，那么得Fever的人就未必得asthma,所以asthma少见。
E的结论不和第二个事实相反嘛，归根结底都是得两病的比率，怎么可以一个高，一个低。
我错在哪？
Over 95 percent of people who have asthma also suffer from hay fever.
有A的人中95%的也患发烧.
Asthma, a bronchial condition, is much less common ailment than hay fever
A比发烧跟普通.
那么在发烧中找出患A病的人按上面比例当然应该小于95%啦.
GWD-12.
Some species of Arctic birds are threatened by recent sharp increases in the population of snow geese, which breed in the Arctic and are displacing birds of less vigorous species. Although snow geese are a popular quarry for hunters in the southern regions where they winter, the hunting season ends if and when hunting has reduced the population by five percent, according to official estimates. Clearly, dropping this restriction would allow the other species to recover.
Which of the following, if true, most seriously undermines the argument?
A. Hunting limits for snow geese were imposed many years ago in response to a sharp decline in the population of snow geese.
B. It has been many years since the restriction led to the hunting season for snow geese being closed earlier than the scheduled date.
C. The number of snow geese taken by hunters each year has grown every year for several years.
D. As their population has increased, snow geese have recolonized wintering grounds that they had not used for several seasons.
E. In the snow goose’s winter habitats, the goose faces no significant natural predation.
答案为B.
A,D,E能排除.B项但是我觉得有问题.(取消限制,将会导致对SNOW GEESE捕猎期更长,杀更多的SG,那么其他鸟越容易回复以前状态)
倒像是在加强.C确挺像答案(越杀越多,反而没有起到抑止效果,继续祸害其他鸟种)
OPEN DISCUSSION!
我开始理解错误，同意你对12题的看法
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不好意思.说得不对的地方,请帮忙改正.
It has been many years since the restriction led to the hunting season for snow geese being closed earlier than the scheduled date
B是说该限制导致对SG的捕猎期比预定时间更早结束,而这一限制已经实施很多年了.那么如果取消的话,对SG的捕猎期无疑会变的比以前长,那么(对于其他鸟的生存)不是有莉吗/.??
还是不在同一版问两个问题，所以我修改了
GWD18-12 请转到
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谁说我15题阿？
GWD18-12 请转到
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Although snow geese are a popular quarry for hunters in the southern regions where they winter, the hunting season ends if and when hunting has reduced the population by five percent
看不懂，谁帮忙翻译一下？
选b: 1） 文章说只要when hunting has reduced the population by five percent，那么hunting season 就会结束，因此，不论是提前结束还是按时结束，都会产生一个相同的结果，就是population of the snow geese was reduced by five percent. 2）文章还有snow geese are a popular quarry for hunters 所以在hunting season 其他birds 也是会捕杀的。由 1，2 可得 hunting season 的提前结束，会给其他birds更多的时间来recover.所以restriction是有利的，也就weaken了结论。
选b: 1） 文章说只要when hunting has reduced the population by five percent，那么hunting season 就会结束，因此，不论是提前结束还是按时结束，都会产生一个相同的结果，就是population of the snow geese was reduced by five percent. 2）文章还有snow geese are a popular quarry for hunters 所以在hunting season 其他birds 也是会捕杀的。由 1，2 可得 hunting season 的提前结束，会给其他birds更多的时间来recover.所以restriction是有利的，也就weaken了结论。
原来是"IF AND WHEN"那句没有读懂.谢谢.
Although snow geese are a popular quarry for hunters in the southern regions where they winter, the hunting season ends if and when hunting has reduced the population by five percent
把红色部分去掉好理解，呵呵
15题，我一朋友的解释：这个用数学集合来解快!
我觉得是，a和b里的prerequisite都是无关信息，从文章里根本推不出来，文章里只说到数据，支持e
up
非常不好意思，把这个题搞成了一个数学题。我画的图传不上来，只好算了一个数说明E是错的。
得了两种病的有98000个人；
只得了Asthma的2000人，只得了hay fever的3000人；
那么按E的说法，百分比应该为98000/(98000+2000+3000)=0.951
5个答案都不像对的，相比之下，B还好点。请高人指点一下
E says the precentage of people who got Hay fever not alludes to the whole precentage of the populations.
amount of people have both Asthema and Hay fever is X
amount of people have Asthema is Y
amount of people have Asthema is Z
we know that Z>Y and X/Y no less than 95%
than what about X/Z? Clearly , it must be less than 95%
So that's way to the answer E.
谢谢gonghao.可是我还有点疑问:就算按你的假设
amount of people have both Asthema and Hay fever is X=98,000
amount of people have Asthema is Y=100,000
amount of people have hay fever is Z=101,000
满足Z>Y and X/Y no less than 95%
than what about X/Z? X/Z=97%>95%
如果说以上设定的Asthma, 还不够 much less common ailment than hay fever，可以假设X=98*10^N(10的N次)，Y＝100*10^N，Z=101*10^N，比例是一样的。
我觉得E的结论是有条件的，不一定得到。把逻辑题弄成MATH绝对不是GMAT的风格，可我真不知道这题考什么?
谢谢.
tasteofbit
终于找到知音了，我感觉这题没有答案。
E答案看似对的，其实也错了.不知道是ETS失误，还是我们理解有误？？
E says the precentage of people who got Hay fever not alludes to the whole precentage of the populations.
amount of people have both Asthema and Hay fever is X
amount of people have Asthema is Y
amount of people have Asthema is Z
we know that Z>Y and X/Y no less than 95%
than what about X/Z? Clearly , it must be less than 95%
So that's way to the answer E.
大大您似乎有不小心打错误
我在这用中文稍微再解释一下好了
因为我门可以从条件一知道: hay fever 花粉并得病的人数大于asthema 气喘人数
条件二知道: 有超过95%得到气喘的人
是从花粉病得到的
所以我门假设
both Hay+Asthema 的人数是X
花粉病的人数是Z
气喘病的人数是Y
条件一推得Z>Y
条件二推得X/Y>95%
所以可以推得X/Z<95%
答案是E ^^
赞同，我也是用这个方法！
原来搞错了E的意思：E的意思应该是得asthma的人在得hay fever人中的比例小于95%，严格来说这个也不严谨，
假设：asthma的数量是X, hay fever的数量是Y,既asthma又hay fever的数量是z
z/x>95%; x<<Y; 所以，z/y<<z/x which is over 95%
这里的关键是asthma是much less than hay fever，要不然用数学是推不出来的
E相对而言好一些。。。。
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