prep2-197没讨论过,我是死活都没想通答案.help!!!

197.            19016-!-item-!-187;#058&012397

The integers m and p are such that 2 < m < p and m is not a factor of p.  If r is the remainder when p is divided by m, is r > 1 ?

(1)  The greatest common factor of m and p is 2.

(2)  The least common multiple of m and p is 30.

答案选A.我选的是D;郁闷

我觉得根据条件2,和提干条件,可以得出两种可能:m=3,p=10   或者m=5,p=6

在这两种情况中p/m,余数r均=1,不是已经充分了吗???

根據條件2，m,p的最小公倍數是30，不是指mp的乘積30吧~

所以如果m,p分別為6,15，餘數不就成了3..所以條件2不充分..

以上

2nd情况：请LZ试想m=6 p=15;m=10 p=15

恩,对的对的,总觉得自己可能是漏了什么,谢谢提醒哈!

prep maths

use following link (bottom of 1st floor is a link to maths prep

http://forum.chasedream.com/dispbbs.asp?BoardID=34&ID=245414&replyID=&skin=1