ChaseDream

标题: 请教GWD1-10,为什么-3不可以呢？ [打印本页]

作者: TASSEL 时间: 2009-3-28 12:21
标题: 请教GWD1-10,为什么-3不可以呢？

A set of numbers has the property that for any number t in the set,t+2 is in the set.If -1 is in the set,which of the following must also be in the set？

I. -3

II. I

III. 5

Why -3 cannot also be in the set since t+2 is in the set? From my point of view,-1's in the set indicate that -3 is also in it.

Is there sth wrong with my logic?

Please help me!

作者: hang13 时间: 2009-3-28 12:26

你可以理解该集合为 X=-1+2n,n>=0

所以X=-1,1,3,5,....

严格按照题干走，别多想

作者: hang13 时间: 2009-3-28 12:27

而且人家问的是“ must also be ”

不是could be，这个区别是相当大滴

作者: TASSEL 时间: 2009-3-28 16:09

明白啦

Thx a lot

欢迎光临 ChaseDream (https://forum.chasedream.com/)