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标题: JJ 73题对于IS题的疑问求权威解释 [打印本页]

作者: abc4686121 时间: 2012-7-15 12:07
标题: JJ 73题对于IS题的疑问求权威解释
73.绝对值的（x/y）=x/y y>0?
(1) x>0
(2)-x>y

如果这道题是is Y>0？

那么条件1肯定可以推出来y>0. 条件2肯定推不出来y>0，是不是选D呢？

作者: duckyhyy 时间: 2012-7-15 21:50
我不权威但是这几天一直在纠结DS题都是自学的和你遇到过同样的困惑到目前为止我得到答案是

DS题中，特殊疑问句必须唯一解才算充分。一般疑问句，能yes或no都算充分

所以这道题就选D啦希望对你有帮助^^

作者: zjzw1988 时间: 2012-7-18 07:47
不会吧，我这里有一道prep的题：

If it took Carlos ½ hour to cycle from his house to the library yesterday, was the distance that he cycled greater than 6 miles? (Note: 1 mile = 5,280 feet)

(1) The average speed at which Carlos cycled from his house to the library yesterday was greater than 16 feet per second.

(2) The average speed at which Carlos cycled from his house to the library yesterday was less than 18 feet per second.

是一般疑问句，两个选项都是说明不会大于6mile,
正确答案是E而不是D！！！

作者: 出国小土鳖 时间: 2012-7-18 10:21

不会吧，我这里有一道prep的题：

If it took Carlos ½ hour to cycle from his house to the library yesterday, was the distance that he cycled greater than 6 miles? (Note: 1 mile = 5,280 feet)

(1) The average speed at which Carlos cycled from his house to the library yesterday was greater than 16 feet per second.

(2) The average speed at which Carlos cycled from his house to the library yesterday was less than 18 feet per second.

是一般疑问句，两个选项都是说明不会大于6mile,
正确答案是E而不是D！！！

-- by 会员 zjzw1988 (2012/7/18 7:47:16)

不是的
I、v>16feet/s=10.9mile/h vt=d d>10.9*1/2=5.45
II、v<18feet/s=12.27mile/s d<6.135
你算错了

作者: wendy0429 时间: 2012-7-18 10:30
这题是选E，因为（1）算出来大概是大于5.45，那可能是大于6miles也可能小于6miles啊，所以不确定，即不充分；条件（2）算出来大概是小于6.14，它也可能大于6或者小于6，也不确定；同理两个条件联立，还是不能确定是大于6还是小于6，所以选E。这题和上面那道题目并不矛盾，我个人认为上面那题选D！
不会吧，我这里有一道prep的题：

If it took Carlos ½ hour to cycle from his house to the library yesterday, was the distance that he cycled greater than 6 miles? (Note: 1 mile = 5,280 feet)

(1) The average speed at which Carlos cycled from his house to the library yesterday was greater than 16 feet per second.

(2) The average speed at which Carlos cycled from his house to the library yesterday was less than 18 feet per second.

是一般疑问句，两个选项都是说明不会大于6mile,
正确答案是E而不是D！！！

-- by 会员 zjzw1988 (2012/7/18 7:47:16)

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作者: 出国小土鳖 时间: 2012-7-18 10:38
不权威，但是大家的讨论都是认为D 我也认为是D
有新的疑问和补充请移步我的帖子呀！
http://forum.chasedream.com/GMAT_Math/thread-737859-1-1.html

作者: ccsyi 时间: 2012-7-18 10:53
我觉得讨论稿上的答案有误吧，这题的意思应该就是问y是否大于0，只要能充分说明y>0或y<0就可以啦，所以选D咯

作者: msbeam 时间: 2012-7-19 16:46
PREP那道题确实是选E，今天才做错，PREP给的答案就是E

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