Thread: Congruence

I am not sure if this is the right place to post this, because this is my first time here, and if it isn't please excuse me.
I've got to solve the following problem due tomorrow and I can't seem to figure it out, the problem is as follows:
"Prove that, for a number a coprime with 2200, a^20 ≡ 1(mod 2200)"
I thank you in advance.

Originally Posted by DonManolo

I am not sure if this is the right place to post this, because this is my first time here, and if it isn't please excuse me.
I've got to solve the following problem due tomorrow and I can't seem to figure it out, the problem is as follows:
"Prove that, for a number a coprime with 2200, a^20 ≡ 1(mod 2200)[FONT[/FONT]

You may not know where to post a question, [But in no case, post it more than once!

I'm sorry, I really don't know the rules, I'm gonna try to delete this post then.Thank you.