求教高手一道逻辑题！

wlmbao

Although the ratio of physicians to total population is about the same in the U.S. and Canada, the U.S. has 33% more surgeons per capita. Clearly, this is the reason people in the US undergo 40% more operations per capita than do Canada.

the explanation given above rests on an assumpyion that:

a)patients in the US do not have a greater need for surgery than do patients in Canada.

b)the population of  US is not larger the that of Canada.

c)US patients sometimes travel to Canada for certain kinds of surgery.

d)general practitioners in US do not as a rule examine a patient who is a candidate for surgery before sending the patient to a surgeon.

e)there are no unnecessary surgical operations performed in Canada.

这是在《gmat逻辑推理-分类思维训练及真题解析〉〉上的，第49页，答案是a,

但是小弟实在是没看明白，最惭愧的是，这本书有中文翻译，我还是找着答案想不出为什莫莱，根本没有思路。

希望高手给讲解一下，拜托了，最好能讲得仔细一点，谢谢了！！！

conniez

I used the elimination to get the answer "A". See my comment in blue highlight below.

Although the ratio of physicians to total population is about the same in the U.S. and Canada, the U.S. has 33% more surgeons per capita. Clearly, this is the reason people in the US undergo 40% more operations per capita than do Canada.

the explanation given above rests on an assumpyion that:

a)patients in the US do not have a greater need for surgery than do patients in Canada. This comment supported the above statement -- "the U.S. has 33% more surgeons per capita".

b)the population of  US is not larger the that of Canada. This comment was against the above statement -- "the ratio of physicians to total population is about the same in the U.S. and Canada".

c)US patients sometimes travel to Canada for certain kinds of surgery. This conclusion cannot be drawn from the orignal given statement. The ratio/total pupulation and No. of surgeons/per capita should be only based on the domestic statistics.

d)general practitioners in US do not as a rule examine a patient who is a candidate for surgery before sending the patient to a surgeon. Again, this conclusion cannot be drawn from the original statement.

e)there are no unnecessary surgical operations performed in Canada. "Unnecessary surgical operations" carries a new piece of information for the original statement.

这是在《gmat逻辑推理-分类思维训练及真题解析〉〉上的，第49页，答案是a,

但是小弟实在是没看明白，最惭愧的是，这本书有中文翻译，我还是找着答案想不出为什莫莱，根本没有思路。

希望高手给讲解一下，拜托了，最好能讲得仔细一点，谢谢了！！！

candy-jing

这题推理思路：因为美国的physicians比例和加拿大的一样，但是每个physicians做手术的量比Canada 多30%--〉美国人比加拿大人多40%的手术（隐含意思为他们更容易出事）。 前提是美国人本身不需要更多的手术， 则以上的推理才成立。

florence1108

我想问一个问题，physicians的意思在这里是泛指所有的医生还是指内科医生呢...？

florence1108

我觉得A可以看做是假设题里排除他因类型的答案，因为手术多可能不单单是医生多一个原因导致的，像手术需求多这种原因也会引起手术多