Coins Again

Alright, new puzzle time. I have a bit of a backlog of decent puzzles, so its important for me to waste them as soon as possible so I go back to not blogging again.

I got this one off of Tanya Khovanova's math blog, well, sort of, I misread the puzzle and solved a variant, but I think the variant is better so I'm going with it:
Athos, Porthos, and Aramis were rewarded with six coins: three gold and three silver. Athos got two coins. Athos doesn’t know what coins the others got, but he knows his own coins and he knows all the coins were given out. Ask him one question to which he can answer “Yes,” “No,” or “I do not know,” so that you will be able to figure out his coins.

My misread was that in the initial puzzle, instead of "Athos got two coins", it was "Each got two coins". My solution worked for both, and I somehow feel that my version is harder (being that you have less information), but its not clear that taking away information from Athos (which my variant also did) actually makes it harder.

Anyway, yeah, its simple, solve it out.


Anonymous said...

Are the two problems actually equally hard?

If you have a solution for the problem where all 3 players get two coins, could you preface it with "Assuming both others got two coins, [...]" to get a solution for your version?

Since he only sees his own two coins, I guess that should work...

Kory Stevens said...

Yeah, thats true, I hadn't considered questions of the form "assuming x, question y".