Supposedly Einstein said that only 2% of the population would be able to solve this riddle without guessing. This IS possible.

Answer of this Riddle is not important but important is what how to get it.  It will definitely improve your problem solving skills.

Riddle Statement

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

The question is: "Who owns the fish?"

Hints:
The Brit lives in the red house.
The Swede keeps dogs as pets.
The Dane drinks tea.
The green house is on the left of the white house.
The green house's owner drinks coffee.
The person who smokes Pall Mall rears birds.
The owner of yellow house smokes Dunhill.
The man living in the center house drinks milk.
The Norwegian lives in the first house.
The man who smokes blends lives next to the one who keeps cats.
The man who keeps horses lives next to the one who smokes Dunhill.
The owner who smokes Bluemasters drinks beer.
The German smokes Prince.
The Norwegian lives next to the blue house.
The man who smokes Blends has a neighbor who drinks water.