有三道数学题，麻烦大家乐，谢谢

songchangwen

Q28:

If n is a positive integer, what is the remainder when (7^{4n + 3})(6ⁿ) is divided by 10 ?

A.1

B.2

C.4

D.6

E.8

Answer:

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Q29:

Is the integer n odd?

(1)n is divisible by 3.

(2)2n is divisible by twice as many positive integers as n.



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.



Q4:

Is the number of members of Club X greater than the number of members of Club Y ?

(1)Of the members of Club X, 20 percent are also members of Club Y.

(2)Of the members of Club Y, 30 percent are also members of Club X.



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. BOTHstatements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.

D. EACH statement ALONE is sufficient.

E. Statements (1) and (2) TOGETHER are NOT sufficient.

gleitta

1.余数用斑竹整理的方法，7^(4n + 3)个位很好判断，3，
6^n个位6，除以10，余数为3x6=18，余数是8

2.一个数x是奇数，则设x=a^m*b^n*c^k，abc都是质数且不为2，则2x=2^1*a^m*b^n*c^k，因数个数为2*（m+1）*（n+1)*(k
+1)，所以必定是x的因数个数的2倍

3.两个集相交，给出了交集在各自所占的比例，两个集的大小比例就有了，实在不行上韦恩图