请问~~ GWD-3-16???

zhangpeiyu01

GWD-3-Q16:

If n is a positive integer and r is the remainder when (n-1)(n+1) is divided by 24, what is the value of r?

(1)     2 is not a factor of n.

(2)     3 is not a factor of n.

                  

答案C.

 

谢谢!

kenlily

n=6k+5/6k+1

这样简单些