There is some question as to whether Albert Einstein is actually responsible for the brain teaser that bears his name. Regardless of whether the white-haired genius created the “Einstein Puzzle” (sometimes called the “Einstein Riddle”), the solution is certainly worthy of someone of his intellect. Are you able to solve it?

• There are 5 houses in five different colors.
• In each house lives a person with a different nationality.
• These five 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 beverage.
• The question is: Who owns the fish?
• These are your 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 the 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 man who smokes Dunhill
• The owner who smokes BlueMaster drinks beer
• The German smokes Prince
• The Norwegian lives next to the blue house
• The man who smokes blend has a neighbor who drinks water.

Question: Who owns the fish?

Scroll down for the answer and an explanation of how to arrive at it.

Answer: The German.

The Solution:

• The possible nationalities are:
  • Norwegian
  • Brit
  • Swede
  • Dane
  • German
• The possible colors are:
  • Red
  • Green
  • White
  • Yellow
  • Blue
• The possible beverages are:
  • Tea
  • Coffee
  • Milk
  • Beer
  • Water
• The possible cigars are:
  • Pall Mall
  • Dunhill
  • Blends
  • BlueMaster
  • Prince
• The possible pets are:
  • Dogs
  • Birds
  • Cats
  • Horses
  • Fish

The Deduction

Well, we know there are five houses. We’ll assume they’re all in a row, and are numbered from left to right. We know the Norwegian is in the first house:

Since the Brit lives in the red house, the Norwegian can’t. We also know the Norwegian lives next to the blue house, so his house isn’t blue. We also know that the green house is to the left of the white house; the Norwegian can’t live in the white house since there is no house to the left, and can’t live in the green house because his only neighbor, the one to the right, is known to live in the blue house. Therefore, the Norwegian lives in the yellow house.

We also know the owner of the yellow house smokes Dunhill, and that the Norwegian has a neighbor with a blue house (the Norwegian only has one neighbor, to the right.)

So here’s what our matrix looks like now:

The man who keeps horses lives next to he man who smokes Dunhill; so the horse owner lives in the blue house. The center house’s owner drinks milk, the green house’s owner drinks coffee, and the green house is to the left of the white house. Since we know the left two houses are the yellow and blue houses, the only position for the green and white are green as the fourth and white as the fifth, since the middle (third) drinks milk and the owner of the green house drinks coffee. The middle house has to be red, and therefore is the Brit’s. So now this is what we know:

The owner who smokes BlueMaster drinks beer; since we know what houses #3 and #4 drink [and neither are beer] and we know what house #1 smokes [and its not BlueMaster], the only possibilities are houses #2 and #5. Keep this information in mind. Since it is evident house #1 cannot drink beer (only house #2 or #5 can), the only possible beverages for house #1 are water and tea, but since the Dane drinks tea, house #1 drinks water. The man who smokes Blends lives next to someone who drinks water; the only house next to #1 (the water-drinking house) is #2. The man who smokes Blends lives next to the one who has cats; so the cat-house is #1 or #3.

Since the Dane drinks tea, he must live in either house #2 or #5. The Swede and German could live in house #2, #4 or #5.

We know the beer-drinker smokes BlueMaster. The only houses that could drink beer are #2 and #5, but since we know that #2 smokes Blends, #5 must be the house which drinks beer and smokes BlueMaster, and #2 has to be the house that drinks tea and the house of the Dane. We can eliminate the possibility of the Dane’s residence being house #5.

We know the German smokes Prince. Therefore, he could not live at house #5 and therefore has to live at house #4. The Swede must live at house #5; we also know house #5 raises dogs since we know the Swede raises dogs, and that house #4 smokes Prince since the German smokes Prince.

The only possibility for house #3’s smokes is Pall Mall; all of the others are taken. We know that whoever smokes Pall Mall raises birds; so house #3 raises birds, and house #1 therefore has cats, since the only houses which could have had cats were #1 and #3, and #3 has been eliminated.

The only remaining pet is the fish, which must be owned by the German. We now know who owns the fish, and have solved the puzzle.

The completed matrix of data is as follows:

Read more fun facts about Albert Einstein.

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