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标题: TT GWD-2-11 帮我看看我的解题思路对不？ [打印本页]

作者: citicsbond 时间: 2006-7-19 11:23
标题: TT GWD-2-11 帮我看看我的解题思路对不？

11. Is the sum of the integers x and y a prime number?

1. x is an even prime number. only 2 is an even prime integer.

2. y is a prime number between 10 and 20. there are 4 prime integers between 10 and 20, they are 11,13,17,19.

so the answer E - statements 1 and 2 together are not sufficient.

各位NN，给个您的意见。

作者: flyingdonna 时间: 2006-7-19 12:59

应该是选E，条件1和条件2相加，19（质数）21（合数）都满足，所以不充分。

作者: citicsbond 时间: 2006-7-19 13:17
yup,quite right.

作者: christlulu 时间: 2006-10-27 17:32

看了

作者: Amber789 时间: 2008-7-15 09:47
不错.

作者: jingle0915 时间: 2010-7-29 20:04
谢谢

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