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标题: TT GWD9 Q32讨论贴又对不上号 [打印本页]

作者: eggegg 时间: 2009-5-2 18:34
标题: TT GWD9 Q32讨论贴又对不上号

不知道为什么总对不上号，我用的是TT31

Q32:

What is the remainder when the positive integer x is divided by 8?

(1) When x is divided by 12, the remainder is 5.

(2) When x is divided by 18, the remainder is 11.

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.

B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.

C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.

D. EACH statement ALONE is sufficient.

E. Statements (1) and (2) TOGETHER are NOT sufficient.

Answer: D E

余数问题总搞不清，大家帮帮偶，谢谢谢谢

作者: 千与千寻117 时间: 2009-5-3 01:17

x=12m+5=18n+11

12m+5+7=18n+11+7

12(m+1)=18(n+1)

2(m+1)=3(n+1)

m=3p-1

x=12(3p-1)+5=36p-7

...so E

作者: eggegg 时间: 2009-5-4 07:53

谢谢千于

作者: hanwenyu9 时间: 2012-12-19 01:08
我实在看不明白这个m=3p-1是怎么推出来的有没有人可以帮帮我 thx a lot!!

作者: Daisssssssy 时间: 2015-12-3 09:16
2(m+1)=3(n+1)表示2(m+1)能被3整除，则（m+1）能被3整除。所以m+1=3p,所以m=3p-1

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