Are You Clever Enough To Solve The World's Toughest Riddle?

It's rumored that only 2% of the world can solve it. Are you in that 2%?

Einstein's Riddle

The Zebra Puzzle, or more commonly known as Einstein's Riddle, is thought of as one of the world's most difficult puzzles. Although it is unclear whether Albert Einstein was actually the creator of the riddle (some also believe Lewis Carrol might have made it), there is little doubt that this puzzle is incredibly difficult!

The Situation

# There are houses in 5 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

Who owns the fish?

The Clues

* 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

The German owns the fish!

The Options

From examining the clues we can deduce that:

The possible nationalities are:

* Norwegian

* Brit

* Swede

* Dane

* German

The possible house 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

Step #1

We know that there are five houses in a row and that the Norwegian is in the first house.

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Step #2

Since the Brit lives in the red house, we know that the Norwegian can't. We also know that the Norwegian's neighbor lives in a blue house so his house also 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, because he can't have any houses to the left of his (since he lives in the 1st house). Nor can he live in the green house because his neighbor to the right lives in a blue house.

Therefore, the Norwegian lives in the yellow house. We can now also say that he smokes Dunhill since the clues say that owner of the yellow house smokes that brand of cigar.

Now our chart will look like this:

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Step #3

The man who keeps horses lives next to the man who smokes Dunhill, so he must live in the blue house. The clues reveal that the center house's owner drinks milk, the green house's owner drinks coffee, and that the green house is to the left of the white house.

Since the middle house (#3) drinks milk, and the green house is to the left of the white house, the green house would have to be house #4 and the white house would have to be house #5.

The middle house would have to be red, and is therefore the Brit's.

This is now what our chart should look like:

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Step #4

Since we know that the owner that smokes BlueMaster drinks beer, and that houses #1, 3, and 4 have different smoking/beverage preferences (from the chart above), we can deduce that this owner is either in house #2 or 5.

Now we know that house #1 cannot drink beer, so the only possible beverage choices left are tea and water. However, we know that the Dane drinks tea, so the Norwegian must drink water.

The man who smokes blends lives next to someone who drinks water, so they must live in the only house next to the Norwegian's -- house #2. The man who smokes blends lives next to the one who has cats, so keep in mind that cats must be house #1 or 3.

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Step #5

Since the Dane drinks tea, he must live in house #2 or 5 (the other being the house of the beer-drinker). The Swede and German could live in house #2, 4, or 5.

The house that drinks beer smokes BlueMaster and since house #2 smokes blends, we know that the beer drinker/BlueMaster smoker must live in house #5.

Therefore, the Dane who drinks tea lives in house #2.

Our updated chart is now:

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Step #6

We know from the clues that the German smokes Prince, so he cannot live in house #5 -- leaving only the Swede to live there (who is said to raise dogs in the clues).

Therefore, the German must live in house #4.

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Step #7

The only possibility of cigar for house #3 is Pall Mall, since all of the others have been taken. We know that the person who smokes Pall Mall also owns birds, so house #3 must raise birds. This would leave house #1 as the only house remaining to raise cats.

Therefore, since the only remaining pet is the fish and the only open spot is with the German, we know that the German must own the fish!

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