[讨论]PREP Math 一道

xiangzhengj

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 n2.

 

不知道这种题怎么来做？ 题也不怎么理解 Thanks

xiangzhengj

答案是B 能解释一下么？ Thanks