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标题: OG49 [打印本页]

作者: gwoo 时间: 2005-5-29 11:28
标题: OG49

A milepost on the towpath read “21” on the side facing the hiker as she approached it and “23” on its back. She reasoned that the next milepost forward on the path would indicate that she was halfway between one end of the path and the other. However, the milepost one mile further on read “20” facing her and “24” behind.

Which of the following, if true, would explain the discrepancy described above?

(A) The numbers on the next milepost had been reversed.

(B) The numbers on the mileposts indicate kilometers, not miles.

(D) A milepost was missing between the two the hiker encountered.

(E) The mileposts had originally been put in place for the use of mountain bikers, not for hikers.

虽然选到了正确答案，但是还是对这替感到很奇怪。大家可以帮忙分析分析吗？

感谢！

作者: 携隐 时间: 2005-5-29 23:42

这里有lawyer的解释：

http://forum.chasedream.com/dispbbs.asp?BoardID=24&replyID=73060&id=73060&skin=0

很多问题其实以前都讨论过的。提问前先搜索一下前人的讨论，可以节省你不少时间：）搜索格式请参考本区置顶的格式贴。

作者: gwoo 时间: 2005-5-30 03:26

感谢！

作者: gwoo 时间: 2005-5-30 03:28

but my OG 49 is not the same as the problem they discussed in that post..

作者: 携隐 时间: 2005-5-30 09:04

我只是看你的标题格式，不像是进行过搜索的，所以提醒你下。你有其他问题可以尽管发问啊不要被我吓回去啦，呵呵。

不过，强烈倡导大家先搜索，然后在原贴后提出自己的问题讨论，这样一个讨论贴才更完整，一个题目从各个角度被讨论，后来的人也比较方便找到自己的要的答案。谢谢支持！

作者: VivienZheng 时间: 2009-7-21 13:49

同问

作者: weiweimiao 时间: 2010-12-4 14:58
能否解释一下这道题的逻辑？

作者: sdcar2010 时间: 2010-12-5 02:33
C is the answer. This is another common sense question.

Originally the hiker assumes that the facing numbers indicate miles from the beginning and the back numbers indicates miles to the end of the path. So he is 21 miles from the beginning and 23 miles from the end. Therefore he reasons that if he advances 1 more mile away from the beginning, the next mile post should have 22 miles on the facing number and 22 miles on the back number, indicating it is the middle point of the path.

But this is not the case. By moving 1 mile away from the beginning, the facing number acturally decreases 1 to 20 miles, while the back number increases 1 to 24 mile. So the 1 mile increase is added to the back number which has to indicate miles from the beginning. Therefore, the facing numbers indicate miles to the end of the path, not miles from the beginning.

作者: melvinperson 时间: 2010-12-5 12:53
sdcar2010 is an awesome guy/girl

作者: alisayangyang 时间: 2012-11-18 14:43
Thanks for sdcar2010's explaination. It's very easy to understand.

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