陈向东的黄皮逻辑-假设专题第30题

lanshichao92

although the ratio of physicians to total population is about the same in the united states and canada, the USA has 33% more surgeons per capita. clearly, this is the reason people in the united states undergo 40% percent more operations per capita than do  canadians.

the explanation given above rests on an assumption that
A. patients in the USA do not have a greater need for surgery than do patients in canada.
B. the population of the USA is not larger than that of canada.
C. USA  patients sometimes travel to canada for certain kinds of surgery.
D. general practitioners in the USA 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.

The answer is A.
我选的是D。
完全不理解A的意思啊~
麻烦各路NN帮忙解释一下~谢谢！

lanshichao92

谢谢！

legnawen

This is a poorly written CR problem.

What the argument establishes is:
1) If more surgeons per capita, then more surgeries per capita.
The assumption for this argument is:
Each surgeon performs the same number of surgeries.

But what the argument wants to say is:
2) Surgeons CAUSES people to undergo surgeries. THEREFORE, more

surgeons, more surgeries.

However, the argument fails to lead to the second argument.

Answer choice A is more a strengthener than a necessary assumption.

queenie924

这题的逻辑是这样子的
原文的推理链：因为美国的 surgeons多，所以美国的手术就多
推出这个结论的假设就是：两国本来的对surgeon的需求是相同的，只是因为美

国的比例大，所以才多
如果你将A取非
则成了美国的需求多过加拿大，那么每股窦娥比例大就不能说明问题了

JoshwuS

"医生总数比例一样"----“美方外科医生比例高于加方”----“美方所做手术比例高于加方”

外科医生的比例高并不代表做手术的需求就高，只有在“加方对做手术需求并不比美方少”的前提下才能解释“美方所做手术比例高于加方”。即A