There are 5 houses in 5 different colors
In each house lives a person with a different nationality
These 5 owners drink a certain type of beverage, smoke a certain brand of cigar, and keep a certain pet
No owners have the same pet, smoke the same brand of cigar or drink the same drink.
Here's the question: Who owns the fish?
Clues
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 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 middle drinks milk
9 The Norwegian lives in the first house
10 The man who smokes Blend lives next door to the one who keeps cats.
11 The man who keeps horses lives next door 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
With these 15 clues the problem is solvable.