Date: Dec 2, 2012 10:47 PM
Author: William Elliot
Subject: Re: No Putnam spoilers please

On Sat, 1 Dec 2012, William Elliot wrote:
> On Sat, 2 Dec 2012, Bart Goddard wrote:
> > William Elliot <marsh@panix.com> wrote in
> >

> > > How do we know if a question is a Putnam question?
> >
> > It'll have the number 2012 in it somewhere.

>
> "What's 5^2012 mod 7?" is a Putnam question? ;-}
>

What the heck, just to add some math, I'll solve it,
Putnam question or not.

phi(7) = 6; 5^2012 = 5^(6 * 335 + 2) = 5^2 = 25 = 4 (mod 7)

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