Terribly sorry. I meant to post something, and the post wasn't going through. For some reason, they just all showed up. I'll post it now. It's a good puzzle, written by Einstein, that is not intrinsically hard but is interesting to do without a pencil and paper. Here it is.
There are 5 houses of 5 different colors. In each house lives a person of a different nationality. Each of the 5 residents drinks a certain type of beverage, smokes a certain brand of cigar, and keeps a certain pet. None of them have the same pet, smoke the same brand of cigar or drink the same beverage.
The question is:
Who owns the fish?
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 resident of the green house drinks coffee.
The person who smokes Pall Mall rears birds.
The resident of the yellow house smokes Dunhill.
The resident of the center house drinks milk.
The Norwegian lives in the first house.
The person who smokes Blends lives next to the one who keeps cats.
The person who keeps the horse lives next to the one who smokes Dunhill.
The person who smokes Bluemasters drinks beer.
The German smokes Prince.
The Norwegian lives next to the blue house.
The person who smokes Blends has a neighbor who drinks water.