作者a2515125 (Bobshih)
看板GMAT
标题[计量]GWD-Quantitative "Set" 请教
时间Fri Aug 21 01:08:14 2009
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. 1
III. 5
A. I only
B. II only
C. I and II only
D. II and III only
E. I, II, and III
答案为d
但是小弟我真的不懂
绿色那本看了几遍SET
还是没有头绪
顷大家跟我指点迷津
--
※ 发信站: 批踢踢实业坊(ptt.cc)
◆ From: 220.129.159.115
1F：推 kaichuan:我想应该是 有t就会有t+2 所以t=1的话 1,3,5,7...都有 08/21 01:15
2F：→ kaichuan:t=-1 所以-1,1,3,5,7.....无止尽下去都有 08/21 01:16
3F：→ a2515125:那哪一行叙述可以得知它是无止尽下去的@@ 08/21 01:19
4F：推 nickyang:只要有t就有t+2，所以有了-1就会有1，有1就会有3，有3就 08/21 01:38
5F：→ nickyang:会有5。t是t+2的充分条件，这题应该是考逻辑 08/21 01:40
6F：→ nickyang:反过来t+2是t的必要条件而非充分条件，所以-3不一定有 08/21 01:41
7F：推 kaichuan:这好像一个电脑语言1=1+1 然後就是无止尽下去了 08/21 01:51
8F：→ a2515125:感恩 08/22 00:24