请教一个DS+一个PS! 跪谢呀!【之前题目贴错了 - - 对不起。。】

cutewen

各位帮忙解答的同学...我错了...我贴错DS了...ORZ...下面这题才是我要问的喔。。对不起大家 - -  


If n is a positive integer and r is the remainder when (n – 1)(n + 1) is divided by 24, what is the value of r?
(1)2 is not a factor of n.
(2)3 is not a factor of 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.


Last year the price per share of Stock X increased by k percent and the earnings per share of Stock X increased by m percent, where k is greater than m.By what percent did the ratio of price per share to earnings per share increase, in terms of k and m?
A.K/M%
B.(k – m) %
C.[100(k – m)] / (100 + k) %
D.[100(k – m)] / (100 + m) %
E.[100(k – m)] / (100 + k + m) %

做了两次还是错了  - -  请赐教!!!

cutewen

正确答案是选  C    和    D喔

buttbutter

就是每股价格对每股收益的的比率增长了多少百分比
比如去年年初股价为a，每股收益为b
那么去年初的每股价格对每股收益的的比率就是a/B
去年末的每股价格对每股收益的的比率是a(1+k%)/b(1+m%)
增长比率的百分比为(（a(1+k%)/b(1+m%)-a/b）/(a/b))100%
你带进去算算就是答案D了~~~

Jason1128

第一题似乎是B

arsenallyr

第一题不是c吧

cutewen

各位！我第一题选的B啊！答案是C  请问是我看的答案错了吗？？

cqrain

n/6 is an integer 难道不可以推出n是integer吗?

cutewen

n/6 is an integer 难道不可以推出n是integer吗?

-- by 会员 cqrain (2010/5/11 0:10:12)

对不起。。我贴错题目了 T.T   应该是这一题选C  我不会做诶。我选的B

cutewen

就是每股价格对每股收益的的比率增长了多少百分比
比如去年年初股价为a，每股收益为b
那么去年初的每股价格对每股收益的的比率就是a/B
去年末的每股价格对每股收益的的比率是a(1+k%)/b(1+m%)
增长比率的百分比为(（a(1+k%)/b(1+m%)-a/b）/(a/b))100%
你带进去算算就是答案D了~~~

-- by 会员 buttbutter (2010/5/10 23:25:01)

感谢MM!!!

nicola997

(1)2 is not a factor of n，得出n是奇数且>=3, 所以(n – 1)(n + 1)是8的倍数
(2)3 is not a factor of n.，得出(n – 1)和(n + 1)至少有一个是3的倍数，因为连续的3个数中一定有一个是3的倍数，所以(n – 1)(n + 1)是3的倍数

(1)(2)单独都不能判断，但两者结合后可知(n – 1)(n + 1)是24的倍数，所以r=0.
所以选C