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.

题意是：n个学生能否平均分到每个教室（m）中

M<13

M与13互质（3 < m）

13n/m得正整数，n/m业得正整数

而条件1 ，3n/m得正整数，3 < m，n/m不见得得正整数

B

 i  see,  thanks @!