GWD27-37 没有搜到讨论

ltwy16323

Q37:

How many different factors does the integer n have?

(1)   n = a⁴b³, where a and b are different positive prime numbers.

(2)   The only positive prime numbers that are factors of n are 5 and 7.

 

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:

答案选的A，但我觉得怎么应该选D呢，请各位给解释一下哈，麻烦了

ltwy16323

自己顶下，真的是不明白啊

barila

我来尝试解答一下吧

Q37:

How many different factors does the integer n have?

(1)   n = a⁴b³, where a and b are different positive prime numbers.

(2)   The only positive prime numbers that are factors of n are 5 and 7.

第一个选项，因为a和b都是质数，所以很明显n的因子就是从集合（1, a, a, a, a, b, b, b）里面选出少于8个元素的乘积，这些可能组成的乘积的个数是固定的，所以得出的n的不同的因子也是固定的

第二个选项，只告诉了质数的因子包括5和7，并不知道n等于几个5以及几个7的乘积，所以上述集合是不确定的，那么n的因子也是不确定的

语言贫乏啊，希望你能看懂我说的

btw，你是自己一个人复习吗？我想征个G友，msn:barila.bai(A) hotmail.com

ltwy16323

谢谢MM，我看懂了哈，我是一个人复习，不过上过的班，而且已经考过一次，16号要考第二次，你是什么样的情况呢