(GWD 31)30-18 答案究竟是什么

vanessav · 发表于 2006-5-26 23:28:00

GWD 31套里面的30套的。似乎搜索不到讨论呢。真是麻烦 31套的似乎没有一个合集讨论帖

Q18:

If k is a positive integer, is k the square of an integer?

(1) k is divisible by 4.

(2) k is divisible by exactly 4 different prime numbers.

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.

Answer: ？

B不是可以得出否么？

bubblelife · 发表于 2006-5-27 00:20:00

我觉得从k is divisible by exactly 4 different prime numbers还是不能得出答案

比如说K＝（2×3×5×7）^2

vanessav · 发表于 2006-5-27 02:28:00

（2 3 5 7 ）^2 可以分解成 22335577，虽然不同的是 4个，K不是可以被 4 或者 9 或者 25 49 等整除了么？

bubblelife · 发表于 2006-5-27 02:49:00

只有4个质数呀，4、9什么的不是质数

yaoyao99 · 发表于 2006-5-27 04:00:00

I'd go with E.

K can be 4 * 3 * 5 * 7, divisible by 4 and also divisible by 2, 3, 5, 7, but not the square of an integer.

可是那么不就是不仅仅 4个数了啊