I ran across a link on SvN to an interesting logic puzzle called Whose Fish?. It purports to be a logic puzzle created by Albert Einstein, and claims Einstein said 98% of the population would not be able to solve it. So naturally, I was intrigued.

The only problem was, the logic matrix for the puzzle doesn’t fit on a single piece of paper, and I don’t have Excel installed. So what did I do? I wrote a CGI script in Ruby that generated a logic matrix using a table of checkboxes, and I wrote some accompanying JavaScript to make it easier to use. Go try it!

If you don’t want to solve the puzzle yourself, feel free to check out some of my steps. Just please, don’t submit this as your own answer. If you’re going to submit an answer, do the work yourself. So anyway, here are some of my steps:

  1. Step
  2. Step
  3. Step
  4. Step
  5. Step
  6. Step
  7. Step
  8. Step
  9. Step

And here’s the final solution.

25 Responses to “Who owns the fish?”
  1. Mike Benonis says:

    That’s pretty cool. It took me about an hour, but I arrived independently at the same answer as you did (and amazingly, I did it without a grid).

  2. Without a grid? Nice. I wouldn’t want to try to keep track of all that without a grid, though.

    I do have to say, I think writing the logic grid was more fun than actually solving the puzzle :)

  3. Mike Benonis says:

    Yeah, basically I drew out the five houses and wrote under each house what it couldn’t be, and went from there. It was messy, but it worked.

  4. Cool puzzle.

    I tried this myself using a spreadsheet and worked on it before I finally solved the puzzle in about an hour.

    In my opinion, the most important clues to solving the puzzle are 1, 4, 5, 8, 10 and 14. Then everything else just sort of fall into place.

  5. Darfluxay says:

    It’s true that you have found german whos pet is unknown, but the question never said German have to have a FISH as a pet. It can be anything. I wonder that’s why Einstein said 98% of the population would not be able to solve it.

  6. Kevin Ballard says:

    Darfluxay – I’ve heard that argument before, and it’s bogus. The problem states one of the pets is a Walleye Pike, which is a kind of fish. And that pet doesn’t belong to anyone else, so yes, the German owns it.

  7. It was very easy and i didn’t have to use 5 minutes

  8. but it was abite confusing

  9. Maggie Haynes says:

    The green House

  10. I found that the puzzle was easy, i did it in 35 minutes duh, it was the germanyou twits.

  11. I have a class of bright ten year olds – the quickest did it in an hour without a complicated grid, I took about ten minutes longer. We used a very simple six column grid.

  12. Kevin Ballard says:

    Hey luke? I’m really glad you know how to make yourself feel better by boasting on the internet. But go take your inane comments elsewhere, please.

  13. paulas@kaplantel.net says:

    I’ve read that it’s not of a surety that Albert Einstein formulated this logic puzzle ‘Who Owns the Fish’, but I have seen several variations of the same. The one that I received stated the fact that the green house was to the left of the white house, neither implying the immediate left nor denyting the far left. My daughter and I both successfully completed the puzzle, each having different outcomes and from our individual perspectives. She, choosing that the problem implied ‘near right’ concluded that the german who lived in the green house (#4) owned the fish. I on the other hand determined that the statement ‘to the left of the white house’ was too broad of a statement. I choose to use the idea of far left and concluded that the Danish in the yellow house (#5) owned the fish. If Einstein indeed formulated this puzzle, it is evident to me that all things are indeed relative, and it is not only a puzzle of logic but one of relitavity and perception. It was a lot of fun!

  14. paulas@kaplantel.net says:

    Sorry for the ‘typo’. I meant to type ‘near left’ and not ‘near right’.

  15. Arrrrggh

  16. This puzzle took me way to long to work through. I must be a 98 %er.

  17. Kevin Ballard says:

    Please don’t post banal comments about how you’re so much smarter than me because you solved it in 20 seconds and are 4 years old. Especially because I never posted how long it took me. I’m just going to delete comments like that.


  19. I did this puzzle in about 20 minutes.. I’m 13, and at first I was getting frustrated because I could not get it. Then after I figured out one thing, everything fell into place.

    I thought doing this was a lot of fun.

    My dad finished the puzzle only a few minutes before me, but he came up with the Norwegian guy.

    I think he started guessing towards the end. =]

    I love logic puzzles, and this was SO much fun.

  20. Antonio Lluvia says:

    I am an 13 years old boy who figure the answer in 1hour 30 seconds.

  21. Hey! I feel quite good to be one of the 2 per cent. Too about 2 hours though.

  22. Some users claim that they have solve in just 20 Minutes . ! Weired

  23. Yeah.. i didn’t use the grid, i drew 5 houses and wrote their details as i went..

    Took me about 30-40 mins.

    great puzzle..

  24. so this took me around an hour or so (im 18) is this this actualy for the very intelligent or is it outdated ??? are we just geting smarter than Einstein predicted plz comment bak, by the way i used like 5 different tables at the same time sloppy but it worked very fun anyone no of any other famous difficult riddles

  25. i did this in about 35 minutes it was quite confusing but certain clues are more important than others…
    the rest just falls into place in the end