Einstein's "Five Houses" Riddle is a well known brain teaser and a good example of how to solve a difficult problem
by breaking it down into a series of solvable steps using logical thinking.
In a street there are five houses in a row, each painted in different colors.
Each house is owned by a person of different nationality.
Each person has a different favourite drink, favourite food and pet.
Einstein's riddle is: Who owns the fish?
The clues are:
The British person lives in a red house.
The Swedish person keeps dogs as pets.
The Danish person drinks tea.
The Green house is next to, and on the left of the White house.
The owner of the Green house drinks coffee.
The person who likes peas rears birds.
The owner of the Yellow house likes cauliflower.
The person living in the middle house drinks milk.
The Norwegian lives in the first house.
The person who likes broccholi lives next to the one who keeps cats.
The person who keeps horses lives next to the person who likes cauliflower.
The person who likes carrots drinks beer.
The German likes potatoes.
The Norwegian lives next to the blue house.
The person who likes broccholi lives next to the one who drinks water.
The German owns the fish
Please note: In the original version, the house owners had favourite cigars.
How to solve Einstein's Riddle:
Click the tickbox to begin ....
Start with a grid and work methodically through the clues, obvious ones first:
House
1
2
3
4
5
Colour
Owner
Drink
Food
Pet
From clue 8, the owner of house 3 drinks milk
From clue 9, the owner of house 1 is Norwegian
From clue 14, house 2 is blue
From clue 4, the green house can now only be house 3 or 4. For clue 5 to work, the green house must be house 4 and so the white house is house 5.
From clue 1, the British owner can now only live in house 3. This also means house 1 is yellow.
From clue 7, the Norwegian likes cauliflower.
From clue 11, the owner of house 2 keeps horses.
From clue 3, the tea drinking Dane could only live in house 2 or 5. From clue 12, the beer drinker could also only live in house 2 or 5. Therefore, the person who drinks water must live in house 1. From clue 15, the person who likes broccholi must live in house 2, and so the Norwegian drinks water.
From clue 10, the cat owner could only live in house 1 or house 3. However, for clue 2, 6 and 13 to all work, the Swede must live in house 4 or 5 and the German must conversely live in house 5 or 4, allowing clue 6 to be satisified in house 3. This leaves the Norwegian as the only person who could keep cats.
From clue 12, this person could now only live at house 5.
From clue 13, the German could now only live at house 4.
From clue 3, the Danish person could now only live at house 2.
From clue 2, the Swedish person could now only live at house 5.