Graeme −> Odds and Ends −> Puzzles −> Einstein quiz 

Below is a quiz written by Einstein last century, sometimes called Einstein's Riddle.  Probably translated and updated since then but the logic is the same.

Einstein said that 98% of the people in the world cannot solve his riddle.  Are you among the other 2%?

1: There are 5 houses in 5 different colors
2: In each house lives a person with a different nationality.
3: These 5 owners drink a certain beverage, smoke a certain brand of cigar and keep a certain pet.
4: No owners have the same pet, smoke the same brand of cigar or drink the same drink.

Further Details:
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 on the immediate left of the white house.
5: The green house owner 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 house right in the center drinks milk.
9: The Norwegian lives in the first house.
10: The man who smokes Blend lives next to the one who keeps cats.
11: The man who keeps horses lives next to the man who smokes Dunhill.
12: The owner 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 Blend has a neighbor who drinks water.

The question is ... WHO KEEPS FISH?

Think about it.  I'm pretty sure you're in the 2% of people who can solve Einstein's Riddle.   But can you solve it elegantly?  In other words, lay out a solution so simply that the rest of us feel like dopes when we see it.  Would you like to see my solution?  Click here for a step-by-step solution.   Try to predict each next step.  Good luck!