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标题: pretest 49-2-7 [打印本页]

作者: huaamy    时间: 2009-10-24 07:30
标题: pretest 49-2-7
Any fruit that is infected is also rotten. No fruit that was inspected in infected. Therefore any fruit that was inspected is safe to eat.

A. It is not safe to eat any fruit that is rotten.
B. It is safe to eat any fruit that is not rotten.
C. It would have been safe to eat infected fruit if it had been inspected.
D. It is not safe to eat any fruit that is infected
E. It is safe to eat any fruit that is uninfected.

I can understand why E is correct.
But why B is wrong? From the question, if infected then rotten. Does that mean that if not rotten then uninfected? If so, then based on B, if not rotten, then safe to eat, can I understand that uninfected is also safe to eat? If so what is the difference between B and E?

Thanks in advance!

作者: TheAssembly    时间: 2009-10-24 15:23

我是准备GMAT的,不过我觉得这题也很有意思

这个题目是找一个暗含假设吧?最终的结论是 调查过的水果是安全的。

题中第二句是“任何调查过的 都是 没感染的”

如果用B“没腐烂的 都是 安全的”的话,就接不上第二句的推理。

要连起来的话,还要一个条件就是“没感染的 都是 没腐烂的”这跟第一句是不同的。因为它是第一句的否命题。否命题不一定正确


作者: TheAssembly    时间: 2009-10-24 15:27

如果要找你的推理的逻辑错误,那就是

调查过的一定是没感染的,但不一定是没腐烂的

就算吃没腐烂的水果安全,也推不出调查过的水果安全


作者: crusoecrusoe    时间: 2009-10-27 21:47

Therefore any fruit that was inspected is safe to eat

Not infected----->Safe

Not infected is not equal to not rotten, so B is wrong.






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