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标题: 求助TTGWD16－7（同TTGWD15-28） [打印本页]

作者: niuniu1438 时间: 2009-4-19 15:24
标题: 求助TTGWD16－7（同TTGWD15-28）

A school administrator will assign each student in a group of n students to one of m classrooms. If 3 < m < 13 < n, is it possible to assign each of the n students to one of the m classrooms so that each classroom has the same number of students assigned to it?

(1) It is possible to assign each of 3n students to one of m classrooms so that each classroom has the same number of students assigned to it.

(2) It is possible to assign each of 13n students to one of m classrooms so that each classroom has the same number of students assigned to it.

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.

答案是B，但是没思路，感觉是D。请求指点

作者: niuniu1438 时间: 2009-4-19 17:21
不是吧～～没人会?

作者: erikajin 时间: 2009-4-19 20:29

其实就是咱平时做那个余数题啊

3 < m < 13 < n n是否能被m整除？

条件一 3n能被m整除

条件二 13n能被m整除

作者: james8419 时间: 2009-4-19 20:59

A school administrator will assign each student in a group of n
students to one of m classrooms. If 3 < m < 13 < n,
is it possible
to assign each of the n
students to one of the m classrooms so that each classroom has the same
number of students assigned to it?

(1) It is possible to
assign each of 3n students to one of m classrooms so that each
classroom has the same number of students assigned to it.

(2) It is possible to
assign each of 13n students to one of m classrooms so that each
classroom has the same number of students assigned to it.

条件一： 3n/m为整数，举反例：当n=20,m=6时，n/m不是整数，所以不能恰好分配到每个班级；当n=18,m=6时，可以，所以不确定，则错。

条件二： 13n/m为整数，因为3<m<13，所以m不可能与13约分成整数，要使13n/m为整数，n/m必为整数，即能整除可以分配。所以选B

作者: niuniu1438 时间: 2009-4-19 21:29
貌似懂了，谢谢～～

作者: gar_bbbbb 时间: 2017-11-7 03:33

james8419 发表于 2009-4-19 20:59
A school administrator will assign each student in a group of nstudents to one of m classrooms.&#160 ...

抱歉时隔这么久翻出来。

题目说：is it possible to assign each of the n students to one of the m classrooms so that each classroom has the same number of students assigned to it?

这算有歧义吗？？条件1虽然不确定但是是有可能的啊。

作者: MrWaiting 时间: 2017-11-7 09:02

gar_bbbbb 发表于 2017-11-7 03:33
抱歉时隔这么久翻出来。

题目说：is it possible to assign each of the n students to one of the m cl ...

你这么说的话说明你对于DS题目还是不够理解，DS题目要的是唯一解，如果不是唯一解就是insufficient。这道题第一个条件对于m来说是3的倍数，那么m会出现3种情况：6，9，12。非唯一解

作者: gar_bbbbb 时间: 2017-11-7 09:33

MrWaiting 发表于 2017-11-7 09:02
你这么说的话说明你对于DS题目还是不够理解，DS题目要的是唯一解，如果不是唯一解就是insufficient。这道 ...

thanks

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