[求助]2道MATH~^O^ 给笨笨的我引导下THX

·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 .

答案是：B   寻求思路？

·If n and m are positive integers, what is the remainder when 3^(4n + 2 + m) is divided by 10 ?
    

(1)n=2

(2)m=1

答案是B？ WHY?

感动一下，谢谢你~~

经你一说还真豁然开朗了，恩，要踏踏实实地学习了。

祝兄台考试顺利~