作者denizee3 (妮)
看板GMAT
标题[计量] PP1-DS-Q3
时间Wed Aug 26 10:31:26 2009
How many different prime numbers are factors of the positive integer n ?
(1) Four different prime numbers are factors of 2n.
(2) Four different prime numbers are factors of n^2.
Answer: B
我看了PP笔记里面的解释
但是我还是不太懂为什麽答案是B
是否可以请各位大大解释这一题的思路
谢谢!
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※ 编辑: denizee3 来自: 68.122.81.73 (08/26 11:57)
1F：推 cs1384:(1) 2n=2*3*5*7 or 2^2*3*5*7 举例 → 掰 08/26 13:58
2F：→ cs1384:(2) 设 n= a*b*c*d 则 n^2=a^2*b^2*c^2*d^2 质数不变 08/26 14:00