I have an ETG test today and it will be roughly 24 hours since I last drank. They say it can go back 80 hours but I have heard different stances on this time frame. I am a 200lb male and workout almost everyday. I only had 3 beers. What are my chances of passing?

Depends on the acceptable levels are to pass, and the terms/agreement between you and the ones ordering the tests. 24 hours is very little time to properly cleanse yourself naturally, and you can expect those 3 beer to be easily detected. I personally don't think you will have enough time to be properly prepared to pass naturally, or by hook, crook, or deception.

So what are the reasons for taking a test to begin with? Was this a test you KNEW was coming, and when?

With 24 hours, you are likely to fail. Who knows, you could get lucky.

Highly unlikely that you'll pass. What do you stand to lose when you fail?