After reading Posting a challenge, and answering it yourself I get a feeling that asking specific known puzzle questions (ignoring the "Self-Answer" part) is not welcome.
I am curious to know, I know this is intended as a Q&A site (what's more Q&A than: what the answer for this XXXX puzzle....), and it will atract both Mathematics/Logic/Puzzle lovers/Experts/Educators/Researchers and plenty other more.
Both experts and layman will benefit from asking these specific questions.
Ignoring the fact that a well known question for one, might be a whole new puzzle for the other, I see no problem allowing such questions.
I don't think we will get questions like:
Having a 1,000 Cubic Liter pool, with 3 hoses that can fill it in 5 hours. If only one hose will work, how long will it take to the pool to fill up?
So I don't see a problem allowing puzzle questions.