(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

As a background to this...I have no experience with proofs at all. I did not take a formal geometry class in high school (took a shortened summer course that gave a VERY brief overview of proofs) and have not gotten to discrete math in university, so I really do not know how to approach/write proofs.

At the top of my homework, it says: "For each problem solution, attempt to adhere to mathematical rigor. Proofs and arguments should be detailed and complete." I've never heard of mathematical rigor and after looking it up I still don't really know how to "conform" to it. Seems like it's some kind of standard for proofs.

Here is one of the questions for my HW:

"Six people enter a room. Either there are three people who know each other or there are three people who are strangers to each other.

Prove the above statement. Where does a variant of the pigeonhole principle come in?"

I don't quite know where to start - I looked up the pidgeonhole principle and didn't really understand how it applies to this problem. Maybe someone can point me in the right direction as to how to write a proof for this problem?

This HW is due Thursday at 11:59 PM EST, help before then is very appreciated.

2. Relevant equations

None that I know of.

3. The attempt at a solution

???

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# Homework Help: Question on proofs for a CS related class

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