扫描二维码，直接登录
题库 / Prep2007E2-DS-21
Is the integer n odd?
(1) n is divisible by 3.
(2) 2n is divisible by twice as many positive integers as n.
Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
EACH statement ALONE is sufficient.
Statements (1) and (2) TOGETHER are NOT sufficient.
还没有题目讲解（毕出老师会陆续发布对官方考题的解读，请保持关注）。
条件2看成了2n的因子数是n的两倍。。
如果n是奇数，那么2就是一个新因子，2n因子数＝（1+1）＊原因子数。
如果n是偶数，那么2包含在原因子里，设n里面有a次方个2，2n的因子数变成（a＋1）＊原因子数，不会一直是2倍
登录 或 注册 后可以参加讨论