It's simple, really.
You comment on the post to answer it.
Sign in using your google id and answer, and the answer will be moderated after a couple of days.
If you don't have a google account, answer with an anonymous id and add your name at the end of it all.
We need your name for the scoreboard, you know.

We have theme rounds as well, and the scoring system for which, will be announced at that point of time.