GWD 16的几道数学题，麻烦大侠们看下：

cll0503

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.
答案：B

Q19:
How many 4-digit positive integers are there in which all 4 digits are even?

A. 625
B. 600
C. 500
D. 400
E. 256
答案：C

Q34:
If 2x2 – y2 = 2xy, then (x + y)2 =

A. x2
B. 3x2
C. 4xy
D. 2y2
E. – y2
答案B

拜托啦，这几题都不会做，汗~

雨落秋池

cll0503 mm,不好意思，我手边没有纸笔，只能帮你回答一下34题

2x2 – y2 = 2xy得出y2=2x2 – 2xy，

(x + y)2 =x2+2xy+y2,把y2=2x2 – 2xy带入得B

qiuhailing01

Q7:问N能否被M整除

条件1:3N能被M整除,因为3 < m < 13 < n, 假如M=6,N=14时,N不能被M整除;当M=6,N=18时,N可能被M整除;不充分;

条件2:13N能被M整除,3 < m < 13 ,M的值均不是13的因子,N必定能被M整除.

qiuhailing01

Q19:将题化为排列组合题:

千位数可选项:2,4,6,8

百位数,十位数,个位数各自可选项: 0,2,4,6,8.

 所以: C41C51C51C51=500, 选C.

cll0503

原来这么简单，看来我的逻辑思维能力真的有问题，谢谢各位了！