请教GWD题，讨论贴没找到，谢谢，急！

GWD16-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.

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GWD16-Q31:

A certain right triangle has sides of length x, y, and z, where x < y < z.  If the area of this triangular region is 1, which of the following indicates all of the possible values of y ?

Ans.      y > 根号2

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GWD19-Q27

A pharmaceutical company received $3 million in royalties on the first $20 million in sales of the generic equivalent of one of its products and then $9 million in royalties on the next $108 million in sales.  By approximately what percent did the ratio of royalties to sales decrease from the first $20 million in sales to the next $108 million in sales?

A.      8%

B.      15%

C.      45%

D.     52%

E.      56%

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GWD20-Q14:

Six cards numbered from 1 to 6 are placed in an empty bowl.  First one card is drawn and then put back into the bowl; then a second card is drawn.  If the cards are drawn at random and if the sum of the numbers on the cards is 8, what is the probability that one of the two cards drawn is numbered 5 ?

A:1/6 B 1/5 C 1/3 D 2/5 E 2/3      ans

Six cards numbered from 1 to 6 are placed in an empty bowl.  First one card is drawn and then put back into the bowl; then a second card is drawn.  If the cards are drawn at random and if the sum of the numbers on the cards is 8, what is the probability that one of the two cards drawn is numbered 5 ?

A:1/6 B 1/5 C 1/3 D 2/5 E 2/3      ans

A.      8%

B.      15%

C.      45%

D.     52%

E.      56%

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GWD20-Q14:

Six cards numbered from 1 to 6 are placed in an empty bowl.  First one card is drawn and then put back into the bowl; then a second card is drawn.  If the cards are drawn at random and if the sum of the numbers on the cards is 8, what is the probability that one of the two cards drawn is numbered 5 ?

A:1/6 B 1/5 C 1/3 D 2/5 E 2/3      ans

Six cards numbered from 1 to 6 are placed in an empty bowl.  First one card is drawn and then put back into the bowl; then a second card is drawn.  If the cards are drawn at random and if the sum of the numbers on the cards is 8, what is the probability that one of the two cards drawn is numbered 5 ?

A:1/6 B 1/5 C 1/3 D 2/5 E 2/3      ans

GWD16-Q31:

A certain right triangle has sides of length x, y, and z, where x < y < z.  If the area of this triangular region is 1, which of the following indicates all of the possible values of y ? Ans.      y > 根号2

是不是因为 XY最大等于2，又已知X<Y，所以Y>根号2 。。。。思路对么，请求指点呀~~

13n能整除ｍ，而ｍ又不可能等于１３，那么只能是ｎ整除ｍ

GWD16-Q7:

其实就是整除性问题：13N可以被M整除，加上条件3 < m < 13 < n，那么N必被M整除

GWD16-Q31:

根据：S=1/2XYSIN90=1，其中X〈Y，     可得Y〉√2

GWD19-Q27

根据题意：（3/20-（9/108））/3/20，50%不到，选C