Einstein’s logic problem

I stumbled upon Albert Einstein’s apparently famous logic problem today. Here’s how it goes.

In a street there are five houses, each painted a different colour. In each house lives a person of a different nationality. These five homeowners each drink a different kind of beverage, smoke a different brand of cigar and keep a different pet.

The question: who owns the fish?

Here are the hints that will help you solve it.

  1. The Brit lives in a red house
  2. The Swede keeps dogs as pets
  3. The Dane drinks tea
  4. The green house is next to, and on the left of the white house
  5. The owner of the green house drinks coffee
  6. The person who smokes Pall Mall rears birds
  7. The owner of the yellow house smokes Dunhill
  8. The man living in the centre house drinks milk
  9. The Norwegian lives in the first house
  10. The man who smokes Blends lives next to the one who keeps cats
  11. The man who keeps horses lives next to the man who smokes Dunhill
  12. The man who smokes Blue Master drinks beer
  13. The German smokes Prince
  14. The Norwegian lives next to the blue house
  15. The man who smokes Blends has a neighbour who drinks water

I used Excel. Purely to organise my thoughts; not for any calculation logic. I reckon you can answer the question (who owns the fish?) without hint 15, but that particular hint gives you a full picture of what everyone drinks.

Let me know how you get on. For those who want to check their answer (against mine at least), go through the following clues, which are hopefully a bit easier.


8 Responses to “Einstein’s logic problem”

  1. Shanahan on December 23rd, 2006 00:35

    I solved this years ago using guess what…EXCEL!!!

    Can you lower the confirmation code digits to say…1? It’s annoying me now.

  2. Dan on December 23rd, 2006 02:02

    Excel rocks.

    As for the reduction in confirmation code length, no. For three reasons:

    1) I have no idea how to. It’s an off-the-shelf plug-in module.
    2) I still get the occasional spam comment. Don’t want to open the floodgates
    3) People should have to work a little to comment on my blog 😉

    Thanks for the Christmas card, btw!


  3. Yehuda on December 26th, 2006 07:52

    I too used Excel, and reduced the number of possibilities to 58. That’s without using hints No. 4, 8 and 9. I wonder how those 3 should translate to further elimination of possible solutions.

  4. Alan on December 28th, 2006 00:34

    Do I get any points for solving it just using your clues? much easier. maybe 1/100th einstein that way? of course, einstein said only 2% of the population would be able to solve his puzzle so that would put me firmly in the 98% category; you must be lonely in the 2% part.

  5. Dan on December 28th, 2006 05:14

    No points for just using my clues. 2% * 6bn = 120m people. Still quite a few people to hang out with!

  6. Bob on February 25th, 2008 09:36

    What is the anwser. I is very cool

  7. Dan on February 25th, 2008 14:14

    The German

  8. rahul on January 25th, 2009 23:00

    Its the german

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