一道不会的GWD

xiahuistacy

Q7:

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.   这个题目答案是B  但是我实在不知道从哪开始解题！请大家帮忙解答！谢谢

a10285

题目浓缩一句话：4《m《12，n》14，m可不可能被n整除？
（1）不能确定，反例，m=12，n=8
（2）确定，13不是m的因子，因此m必定是N的因子才能被13n整除~
B