The Zebra Puzzle is a logic puzzle said to be invented by Albert Einstein (but who knows), and Wikipedia says that only 2% of the world population is able to solve it (also who knows, but it really made me want to solve it). Here’s how it goes:
The puzzle consists of five different-colored houses in a row, each lived in by a resident of a different nationality. Each resident owns a different pet, prefers a different drink, and smokes a different brand of cigarettes than the others.
You’re given 15 other facts:
- There are five houses.
- The Englishman lives in the red house.
- The Spaniard owns the dog.
- Coffee is drunk in the green house.
- The Ukrainian drinks tea.
- The green house is immediately to the right of the ivory house (to your right as you stand facing the row of five houses).
- The Old Gold smoker owns snails.
- Kools are smoked in the yellow house.
- Milk is drunk in the middle house.
- The Norwegian lives in the first house.
- The man who smokes Chesterfields lives in the house next to the man with the fox.
- Kools are smoked in a house next to the house where the horse is kept.
- The Lucky Strike smoker drinks orange juice.
- The Japanese smokes Parliaments.
- The Norwegian lives next to the blue house.
To solve the puzzle, tell me:
1) Which man likes to drink water
2) Which man owns a zebra
And for those who got it, how did you do it?
[expand title=”Tim’s Solution (click to reveal)”]
Okay here’s how I did it.
I started by making a spreadsheet:
Then I looked at the 15 facts to find anything I could fill into the grid with certainty.
There were facts 9 and 10, which stated flat out that milk is drunk in House 3 and the Norwegian lives in House 1. Fact 15 puts the blue house as House 2.
Those were like the numbers they give you to start a Sudoku puzzle. Using that info plus fact 6 (the green house is immediately to the right of the ivory house) I knew that the ivory-green houses had to either be Houses 3-4 or 4-5, leaving only red and yellow as possible colors for House 1. Fact 2 told me that the red house was where the Englishman lived, so that left only yellow for House 1. That then led me to fact 8 (Kools are smoked in the yellow house) and fact 12 (Kools are smoked next to the house with the horse), allowing me to fill in six items for sure:
From there, I started creating “color blocks.” When a fact would tell me that two items on the grid were linked together, I’d put them in somewhere they could fit and make them the same color. I could then treat each color group like a single puzzle piece.
Once all the puzzle pieces were created, it was just a matter of shifting them around horizontally until they all fit.
That left two empty white squares, revealing the answers:
1) The Norwegian drinks water
2) The Japanese guy has a pet zebra
There will be no Dinner Table next Sunday.