Fellow puzzlers and PuzzleNationers, it’s time to put on our thinking caps and crack another puzzly mystery!

I’ve seen this riddle making the rounds online lately, and like many logic problems, puzzles, and brain teasers that go viral, it claims that 98% of the world couldn’t solve it!

Well, I don’t buy that. (I also don’t buy that Einstein created it or had anything to do with it, but since it circulates under the name “Einstein’s Riddle,” I’m also calling it such.)

[Image courtesy of Mental Floss.]

Einstein’s Riddle

• There are five houses that are each a different color.
• There is a person of a different nationality in each house.
• The five owners drink a certain drink. They each smoke a certain brand of cigar and also have a certain pet. No owner has the same pet, smokes the same brand of cigars, nor drinks the same drink.

CLUES

1. The British man lives in the red house.
2. The Swedish man has a dog for a pet.
3. The Danish man drinks tea.
4. The green house is on the left of the white house.
5. The owner of the green house drinks coffee.
6. The person that smokes Pall Mall raises birds.
7. The owner of the yellow house smokes Dunhill.
8. The person that lives in the center house drinks milk.
9. The Norwegian lives in the first house.
10. The person that smokes Blend lives next to the one that has a cat.
11. The person that has a horse lives next to the one that smokes Dunhill.
12. The one that smokes Bluemaster drinks beer.
13. The German smokes Prince.
14. The Norwegian lives next to a blue house.
15. The man that smokes Blend has a neighbor that drinks water.

The question is “who owns the fish?”

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Now, the first step is going through the clues and getting all five options for every variable. This will help us with the second step: building a grid to help us organize information.

• Colors: Blue, Green, Red, White, Yellow
• Nationalities: British, Danish, German, Norwegian, Swedish
• Beverages: Beer, Coffee, Milk, Tea, Water
• Cigars: Blend, Bluemaster, Dunhill, Pall Mall, Prince
• Pets: Birds, Cat, Dog, Fish Horse

Okay, let’s build our grid. Now, we could list every intersection of information, like a full logic problem grid, but I don’t think that’s necessary here. We can simplify.

So where do we start? Well, since several clues refer to a first house, a center house, or neighboring houses, let’s assume that we’re talking about five houses in a row, and use that as our top line. Then we can list all of the other categories we need to determine along the left side.

Now let’s fill in what we know from the clues. We know the Norwegian lives in the first house (clue #9), the man living in the center house drinks milk (clue #8), and the Norwegian lives next to the blue house (clue #14).

This might not seem like much, but we can already determine what color the Norwegian’s house is. The British man lives in the red house (clue #1), so the Norwegian’s house isn’t red. The green house is on the left of the white house (clue #4), so the Norwegian’s house is neither green nor white, since there’s no house to the left of the Norwegian’s house, and the house to the right is blue. Therefore, the Norwegian’s house is yellow, the only color left.

And that tells us something else. The owner of the yellow house smokes Dunhill (clue #7), so we know what the Norwegian smokes. Plus, the man who keeps the horse lives next to the man who smokes Dunhill (clue #11), so we know the pet for the blue house.

We can now determine the color for every house. The green house is to the left of the white house (clue #4), and the owner of the green house drinks coffee (clue #5). But since we already know the owner of the center house drinks milk, that means the green house has to be the fourth, and the white house the fifth. Therefore, the center house is red.

But that’s not all we know now! The British man lives in the red house (clue #1), so we can place him as well.

Hmmm, where do we go from here? Well, let’s take a look at the beverages. We know the Norwegian doesn’t drink coffee or milk, but we also know that the Danish man drinks tea (clue #3), so the Norwegian doesn’t. We also know that the one that smokes Bluemaster drinks beer (clue #12), and the Norwegian smokes Dunhill, so that eliminates beer. Therefore, the Norwegian drinks water.

Since the man that smokes Blend has a neighbor that drinks water (clue #15), we can place Blend in the second house. (Clue #10 tells us that the person that smokes Blend lives next to the one that has a cat, but right now, we can’t be sure if that’s the first house or the center house, so let’s table that clue for now.)

But remember clue #12, the one that smokes Bluemaster drinks beer? Well, we know all the drinks except the second house and the fifth house, and the owner of second house smokes Blend, so the owner of the fifth house must both smoke Bluemaster and drink beer.

That leaves tea as the only possible beverage for the second house, and the Danish man drinks tea (clue #3), so we can place him as well.

Now we’re cooking! The German smokes Prince (clue #13), and since we know the nationality of the third house’s owner and what the fifth house’s owner smokes, the only option remaining is the fourth house. By process of elimination, that also places the Swedish man in the fifth house and Pall Mall in the center house.

And we’re left with only the pets to place. Appropriate, given that the question that got us started is “who owns the fish?”

According to clue #2, the Swedish man has a dog for a pet, and the person that smokes Pall Mall raises birds, so that takes care of the center and fifth houses, leaving only the first house and the fourth.

Clue #10, the one we put aside earlier, now comes into play. The person that smokes Blend lives next to the one that has a cat, and since the neighbor on one side (the center house) raises birds, that leaves only the first house open to have a cat.

Therefore, the German man — who smokes Prince, drinks coffee, and lives in the green house — also owns a fish.

98% of people can’t solve it? Apparently, I have greater faith in solvers than “Einstein” did.

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