Who owns the fish? Einstein’s riddle with a step-by-step solution

This is the version of Einstein’s riddle that circulates most widely online: five houses, five nationalities, and one question, who owns the fish? It is a reworking of the 1962 zebra puzzle with different brands and pets, and it is just as solvable by pure logic.

The puzzle

There are five houses in a row, each painted a different colour. In each lives a man of a different nationality. The five owners each drink a certain drink, smoke a certain brand and keep a certain pet. No two owners have the same pet, brand or drink.

The Brit lives in the red house.
The Swede keeps dogs as pets.
The Dane drinks tea.
The green house is directly to the left of the white house.
The owner of the green house drinks coffee.
The person who smokes Pall Mall keeps birds.
The owner of the yellow house smokes Dunhill.
The man living in the centre 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 man who smokes Dunhill.
The man who smokes Bluemasters drinks beer.
The German smokes Prince.
The Norwegian lives next to the blue house.
The man who smokes Blends has a neighbour who drinks water.

House 1 is on the left. “Next to” means directly beside, and “directly to the left” means the next house along.

Show the step-by-step solution

Start with the fixed facts. The Norwegian is in house 1 (clue 9) and the centre house, house 3, drinks milk (clue 8). The Norwegian’s only neighbour is house 2, so house 2 is blue (clue 14).
Place green and white. Green is directly left of white (clue 4). Green can’t be house 2 (blue) or house 3, because the green house drinks coffee (clue 5) and house 3 drinks milk. Green can’t be house 1 either, because then white would be house 2. So green is house 4 and white is house 5.
Yellow and red. The Brit lives in the red house (clue 1), so red is not house 1, where the Norwegian lives. Houses 1 and 3 hold red and yellow, so house 1 is yellow and house 3 is red, with the Brit.
Dunhill and horses. The yellow house smokes Dunhill (clue 7), so house 1 smokes Dunhill, and the horses live next door in house 2 (clue 11).
House 1 drinks water. The Norwegian doesn’t drink tea (that’s the Dane, clue 3), coffee (house 4) or milk (house 3). Beer goes with Bluemasters (clue 12), but house 1 smokes Dunhill. Water is the only drink left.
Blends is house 2. The Blends smoker has a neighbour who drinks water (clue 15). House 1’s only neighbour is house 2.
The Dane is in house 2. Tea and beer are left for houses 2 and 5. House 2 smokes Blends, not Bluemasters, so it can’t drink beer (clue 12). House 2 drinks tea, so the Dane lives there (clue 3), and house 5 drinks beer and smokes Bluemasters.
The German and the Swede. Houses 4 and 5 hold the German and the Swede. The German smokes Prince (clue 13) and house 5 smokes Bluemasters, so the German is in house 4 with Prince and the Swede is in house 5 with the dogs (clue 2).
Birds and cats. The only brand left, Pall Mall, goes to house 3, which keeps birds (clue 6). The cats are next to Blends in house 2 (clue 10), so they are in house 1 or 3; house 3 has birds, so the cats are in house 1.
The fish. The only pet left is the fish, and the only house without a pet is house 4.

The German owns the fish.

House	Colour	Nationality	Drink	Smoke	Pet
1	Yellow	Norwegian	Water	Dunhill	Cats
2	Blue	Dane	Tea	Blends	Horses
3	Red	Brit	Milk	Pall Mall	Birds
4	Green	German	Coffee	Prince	Fish
5	White	Swede	Beer	Bluemasters	Dogs

Why this version is everywhere

The fish version swaps the zebra for a fish, Kools and Old Gold for Dunhill and Blends, and the five nationalities for European ones. The logic is the same shape: two fixed facts, one forced colour, then a long chain of eliminations. The claim that only 2% of people can solve it has no source, and plenty of people solve it with a pencil and twenty minutes.

For the original, see the 1962 zebra puzzle walkthrough, or read both answers explained side by side.

Want another one?

Lantern Lane publishes a new puzzle in this style every day, and the hard Einstein riddles are the same size as this one.

Play today’s puzzle