The Albert Einstein Riddle is a famous logic puzzle said to be formulated by the theoretical physicist when he was young. First published in Life International in 1962, it gives 15 clues about a set of neighbors, then it asks a seemingly unanswerable question about one or more of them.
More than one version of the puzzle exists, but 15 clues derived from the 1962 Life International magazine version are as follows:
1. There are five different color houses.
2. An Englishman lives in the red house.
3. A Spaniard owns a small dog.
4. Coffee is drunk inside the dark green house.
5. An Ukrainian drinks hot tea.
6. The dark green house is immediately to the right of the bright ivory house.
7. An Old Gold smoker owns two snails.
8. Reds are smoked in the bold yellow house.
9. Chocolate milk is drunk in the middle house.
10. A Norwegian lives in the first house.
11. A gentleman who smokes Chesterfields lives in the house next to the gentleman with the fox.
12. Reds are smoked in the house next to the house where the horse lives.
13. The Lucky Strike smoker drinks fresh orange juice.
14. The Japanese smokes a pack of Parliaments everyday.
15. The Norwegian lives next to the big blue house.
Now, who drinks sparkling water? Who owns the wild zebra?
The solutions to the two final questions are deducible from the 15 clues. The riddle requires one to deduce which nationality lives in which house, who smokes which cigarette, who owns which pet, who drinks which beverage, and in what order each color house is.
Different variations on the riddle alter the clues but not the essential logic. According to Stanford University, it is popularly claimed that only 2 percent of the population can solve the riddle.