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Posted June 25, 2024 By Presh Talwalkar. Read about me, or email me.
Legend says that Einstein invented this puzzle as a child. The following puzzle is adapted from the version in Life Magazine, 1962.
1. There are 5 homes in a row numbered 1 to 5. Each house is painted a different color and has individuals of different countries, each owning different pets, drinking different beverages, and enjoying different brands of candy.
2. The Englishman lives in the red house.
3. The Spaniard owns the dog.
4. Coffee is drunk in the green house.
5. The Ukrainian drinks tea.
6. The green house is numbered one more than the ivory house.
7. The person who eats M&Ms owns snails.
8. Kit Kats are eaten in the yellow house.
9. Milk is drunk in home 3.
10. The Norwegian lives in home 1.
11. The man who eats Cadbury’s lives in the house next to the man with the fox.
12. Kit Kats are eaten in the house next to the house where the horse is kept.
13. The Snickers eater also drinks orange juice.
14. The Japanese enjoys Reese’s candy.
15. The Norwegian lives next to the blue house.
Now, who drinks water? And who owns the zebra?
As usual, watch the video for a solution.
Or keep reading. "All will be well if you use your mind for your decisions, and mind only your decisions." Since 2007, I have devoted my life to sharing the joy of game theory and mathematics. MindYourDecisions now has over 1,000 free articles with no ads thanks to community support! Help out and get early access to posts with a pledge on Patreon.
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Answer To Einstein Riddle Logic Puzzle
(Pretty much all posts are transcribed quickly after I make the videos for them–please let me know if there are any typos/errors and I will correct them, thanks).
Set up a grid with the characteristics of house, color, country, pet, beverage, and candy. From clues 1, 9, 10, 15 you can put milk in house 3, Norway in house 1, and then blue for house 2.
I then proceeded to clue 6 which is the green house is 1 more than the ivory house, so that ivory-green can be houses 3-4 or 4-5. From clue 4 coffee is in the green house, and from clue 2 there is only one spot in each grid for color-country slots for red-England. This means house 1 is the remaining color option yellow, which from clue 8 must be the Kit Kat candy. From clue 12 the horse is next to the Kit Kat house so it is in house 2.
From clue 5 the Ukrainian drinks tea. This is house 2 for the top grid, and houses 2 or 4 in the second. Clue 13 has the Snickers eater drinks orange juice, which can be in house 5 in the top grid, or the remaining spot of house 2 or 4 in the bottom grid. In either case, houses 2 to 5 have beverages all filled, leaving house 1 to be the remaining beverage of water. Therefore the Norwegian drinks water.
We can eliminate the third grid in the following steps. Clue 3 the Spaniard owns the dog must be house 5, which means Japan for house 2. But that implies Japan-Snickers which contradicts clue 14 the Japanese enjoys Reese’s.
The first grid can be eliminated with a bit more effort. Clue 3 the Spaniard owns the dog could be in house 3 (or 4) in the top grid, leaving Japan-Reese’s for house 4 (or 3). The only candy slots for M&Ms are 2 and 4 (or 3), but those homes already have pets of horse and dog. So it would not be possible to have clue 7 which is M&Ms – snails. Therefore the first grid is not possible. Only the second grid can work.
From clue 14 we have Japan-Reese’s in house 5, meaning Spain is house 4. Clue 3 puts the dog with Span in house 4. Only house 3 can then satisfy clue 3 of M&Ms-snails. So house 2 must have the last candy of Cadbury’s. Clue 14 then puts the fox in the next house, which must be house 1. This leaves the zebra in house 5.
Therefore the Norwegian drinks water, and the Japanese has the zebra. And that’s the answer!
Reference
Zebra Puzzle/Einstein Riddle on Wikipedia
Life Magazine, 1962.
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