I found this math question: How to make 21?. I wanted to answer, but I found out that a copy of this riddle was on another question site, precisely here.
Apart from any wonder of plagiarism, If I were the question author, I would like to award people who really spent time trying to figure out how to solve this riddle, instead of people who simply made a Google search.
how can I treat the answer I would get in a similar question? Would you anyway accept the first correct one, or give no correct answer at all (explaining why in a question edit)?