Einstein's Riddle — Step-by-step tutorial on how to solve the world's hardest puzzle

Also known as "Zebra Puzzle", this riddle is said to have been invented by Albert Einstein in the late 19th century. Also, it's said that 98% of the world's population can't solve it.

Rather than bore you with the text and tell you to solve on the paper and pencil, I'm going to recommend that you solve on our website. There you can try different approaches and get instant feedback telling you if there's any logical error.

Click here to go to Brainzilla.com and solve the Einstein's Riddle.

Try to solve it first, it can be challenging but I guarantee it's worth!

Gave up? No problem, just follow the reasoning on how to solve the Zebra Puzzle in 10 steps:

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Let's start by going at the obvious clues:

• The man living in the centre house drinks Milk.
• The Norwegian lives in the first house.

After marking these two clues on the board, you'll be able to use this other clue:

• The Norwegian lives next to the Blue house.

The board after filling in the first 3 clues

Next, we'll be looking at these two clues:

• The Green house is next to the White house, on the left. (1)
• The owner of the Green house drinks Coffee. (2)

Since the Green house is on the left of the White house, it can't be the first house (as the house right next of it is blue), obviously can't be the second house because it's blue, and for sure can't be the last one, because it has to be on the left of another house. By using (2), we can see that it also can't be the house of the middle (because the gentleman who lives there likes to drink milk). Therefore, the Green house is the fourth house, its owner likes Coffee and the 5th house is White.

After using two more clues

Now, check out this clue:

• The Brit lives in the Red house.

It's clear that the Brit doesn't live in the first house (the Norwegian lives there), and the only other house that can be red is the middle one. So the Brit lives there and its color is red. Also, by elimination, the first house must be Yellow.

After filling the Brit's, the red and yellow houses.

Now you can fill these trivial clues on houses #1 and #2:

• The owner of the Yellow house smokes Dunhill.
• The man who keeps Horses lives next to the man who smokes Dunhill.

Now, let's analyze these two clues and focus on the first house:

• The Dane drinks Tea.
• The man who smokes Blue Master drinks Beer.

Since we have 5 different drinks, two of them are filled on the board (milk and coffee, on houses #3 and #4, respectively) and both Tea and Beer can't be placed in the first house (as there lives the Norwegian and he likes Dunhill), it follows that the Norwegian likes to drink Water.

Just after finding that the Norwegian likes to drink water

Lets focus on this clue:

• The man who smokes Blends has a neighbour who drinks Water.

Since the only neighbor of the gentleman who drinks Water live in the house #2, the person on the second house smokes Blends. Right after filling this one, we see that this other clue can be used:

• The man who smokes Blue Master drinks Beer.

The man who smokes Blue Master can't live in the first or second houses, since they like to smoke Dunhill and Blends, respectively. Also, he can't live in the third and fourth houses, as their owners likes to drink Milk and Coffee. Therefore, the gentleman on the House #5 drinks Beer and smokes Blue Master.

After filling the drink and cigarette on the last house

Now we can see that the owner of the Blue house can only drink Tea, so let's mark that. Now, this clue becomes useful:

• The Dane drinks Tea.

Now we just filled the info about the Dane/Tea on the house #2

Let's what this clue can tell us:

• The German smokes Prince.

We can see that the German can only live in the last two houses (the only ones that we don't know the nationality yet). Also, the owner of the House #5 smokes Blue Master, therefore, in the House #4 lives the German and he likes to smoke Prince.

Right after that, we can see that the owner of the fifth house must be the Swede (the only nationality remaining) and:

• The Swede keeps Dogs as pets.

It then follows that the Swede, the gentleman living in the last house, keeps Dogs as pets.

After filling all the info about the Swede and the German

Now it's clear that the man who lives in the House #3 likes to smoke Pall Mall and this next clue tells us that he rears Birds:

• The person who smokes Pall Mall rears Birds.

After figuring out that the gentleman of the middle rears Birds and likes Pall Mall

And that's it! The last clue:

• The man who smokes Blends lives next to the one who keeps Cats.

Since the neighbor of the right of the House #2 has birds, the gentleman of the first house must have Cats. And the German of the House #4 must have Fish as a pet.

Finally, the complete Zebra Puzzle (Einstein's Riddle) answer

That's it, I hope you enjoyed and if you liked you can play other types of Zebra Puzzles on our website.