1. The Zebra Puzzle is a well-known logic puzzle.

It is often called "Einstein's Puzzle" or "Einstein's Riddle" because it is said to have been invented by
Albert Einstein as a boy. Some claim that Einstein said "only 2 percent of the world's population can solve it". It is also sometimes attributed to Lewis Carroll. However, there is no known evidence for Einstein's or Carroll's authorship.

There are several versions of this puzzle. The version below is quoted from the first known publication in Life International magazine on December 17, 1962. The March 25, 1963, issue contained the solution given below and the names of several hundred solvers from around the world.

The original puzzle
There are five houses.
The Englishman lives in the red house.
The Spaniard owns the dog.
Coffee is drunk in the green house.
The Ukrainian drinks tea.
The green house is immediately to the right of the ivory house.
The Old Gold smoker owns snails.
Kools are smoked in the yellow house.
Milk is drunk in the middle house.
The Norwegian lives in the first house.
The man who smokes Chesterfields lives in the house next to the man with the fox.
Kools are smoked in the house next to the house where the horse is kept.
The Lucky Strike smoker drinks orange juice.
The Japanese smokes Parliaments.
The Norwegian lives next to the blue house.

Now, who drinks water? Who owns the zebra?

In the interest of clarity, it must be added that each of the five houses is painted a different color, and their inhabitants are of different national extractions, own different pets, drink different beverages and smoke different brands of American cigarettes. One other thing: In statement 6, right means your right.

Discussion
The premises leave out some details, notably that the houses are in a row.

Since neither water nor a zebra is mentioned in the clues, there exists a reductive solution to the puzzle, namely that no one owns a zebra or drinks water. If, however, the questions are read as “Given that one resident drinks water, which is it?” and “Given that one resident owns a zebra, which is it?” then the puzzle becomes a non-trivial challenge to inferential logic. (A frequent variant of the puzzle asks “Who owns the fish?”)

It is possible not only to deduce the answers to the two questions but to figure out who lives where, in what color house, keeping what pet, drinking what drink, and smoking what brand of cigarettes.

Rule 12 leads to a contradiction. It should have read "Kools are smoked in a house next to the house where the horse is kept." (Note "a" instead of "the.") The text above has been kept as it is, as it is meant to be a presentation of the text of the puzzle as originally published.

Rule 11 suffers from a similar problem as that just described regarding rule 12.

Solution
house 1 2 3 4 5
color yellow blue red ivory green
nationality Norwegian Ukrainian Englishman Spaniard Japanese
drink WATER tea milk orange juice coffee
smoke Kools Chesterfield Old Gold Lucky Strike Parliament
pet fox horse snails dog ZEBRA

Here are some deductive steps that you can follow to derive the solution. A useful method is to try to fit known relationships into a table and eliminate possibilities. Key deductions are in italics.

STEP 1

We are told the Norwegian lives in the 1st house (10). It does not matter whether this is counted from the left or from the right. We just need to know the order, not the direction.

From (10) and (15), the 2nd house is Blue. What color is the 1st house? Not Green or Ivory, because they have to be next to each other (6). Not Red, because the Englishman lives there (2). Therefore the 1st house is Yellow.

It follows that Kools are smoked in the 1st house (8) and the Horse is kept in the 2nd house (12).

So what is drunk by the Norwegian in the 1st, Yellow, Kools-filled house? Not Tea since the Ukrainian drinks that (5). Not Coffee since that is drunk in the Green house (4). Not Milk since that is drunk in the 3rd house (9). Not Orange Juice since the drinker of Orange Juice smokes Lucky Strikes (13). Therefore it is Water (the missing beverage) that is drunk by the Norwegian.

STEP 2

So what is smoked in the 2nd, Blue house where we know a Horse is also kept?

Not Kools which are smoked in the 1st house (8). Not Old Gold since that house must have Snails (7).

Let's suppose Lucky Strikes are smoked here, which means Orange Juice is drunk here (13). Then consider: Who lives here? Not the Norwegian since he lives in the 1st House (10). Not the Englishman since he lives in a Red house (2). Not the Spaniard since he owns a dog (3). Not the Ukrainian since he drinks tea (4). Not the Japanese who smokes Parliaments (14). Since this is an impossible situation, Lucky Strikes are not smoked in the 2nd house.

Let's suppose Parliaments are smoked here, which means the Japanese man lives here (14). Then consider: What is drunk here? Not Tea since the Ukrainian drinks that (4). Not Coffee since that is drunk in the Green house (4). Not Milk since that is drunk in the 3rd house (9). Not Orange Juice since the drinker of that smokes Lucky Strike (13). Again, since this is an impossible situation, Parliaments are not smoked in the 2nd house.

Therefore, Chesterfields are smoked in the 2nd house.

So who smokes Chesterfields and keeps a Horse in the 2nd, Blue house? Not the Norwegian who lives in the 1st House (10). Not the Englishman who lives in a Red house (2). Not the Spaniard who owns a dog (3). Not the Japanese who smokes Parliaments (14). Therefore, the Ukrainian lives in the 2nd House, where he drinks Tea (5).

STEP 3

Since Chesterfields are smoked in the 2nd house, we know from (11) that the Fox is kept in either the 1st house or the 3rd house.

Let us first assume that the Fox is kept in the 3rd house. Then consider: what is drunk by the man who smokes Old Golds and keeps Snails (7)? We have already ruled out Water and Tea from the above steps. It cannot be Orange Juice since the drinker of that smokes Lucky Strikes (13). It cannot be Milk because that is drunk in the 3rd house (9), where we have assumed a Fox is kept. This leaves Coffee, which we know is drunk in the Green house (4).

So if the Fox is kept in the 3rd house, then someone smokes Old Golds, keeps Snails and drinks Coffee in a Green house. Who can this person be? Not the Norwegian who lives in the 1st house (10). Not the Ukrainian who drinks Tea (5). Not the Englishman who lives in a Red house (2). Not the Japanese who smokes Parliaments (14). Not the Spaniard who owns a Dog (3).

This is impossible. So it follows that the Fox is not kept in the 3rd house, but in the 1st house.

STEP 4

From what we have found so far, we know that Coffee and Orange Juice are drunk in the 4th and 5th houses. It doesn't matter which is drunk in which; we will just call them the Coffee house and the Orange Juice house.

So where does the man who smokes Old Gold and keeps Snails live? Not the Orange Juice house since Lucky Strike is smoked there (13).

Suppose this man lives in the Coffee house. Then we have someone who smokes Old Gold, keeps Snails and drinks Coffee in a Green (4) house. Again, by the same reasoning in STEP 3, this is impossible.

Therefore, the Old Gold-smoking, Snail-keeping man lives in the 3rd house.

It follows that Parliaments are smoked in the Green, Coffee-drinking house, by the Japanese man (14). This means the Spaniard must be the one who drinks Orange Juice, smokes Lucky Strikes and keeps a Dog. By extension, the Englishman must live in the 3rd house, which is Red. By process of elimination, the Spaniard's house is the Ivory one.

By now we have filled in every 'blank' except one, and it is clear that the Japanese is the one who keeps the Zebra.

right-to-left solution
The above solution assumed that the first house is the leftmost house. If we assume that the first house is the rightmost house, we find the following solution. Again the Japanese keeps the Zebra, and the Norwegian drinks water.

house 5 4 3 2 1
color ivory green red blue yellow
nationality Spaniard Japanese Englishman Ukrainian Norwegian
drink orange juice coffee milk tea WATER
smoke Lucky Strike Parliament Old Gold Chesterfield Kools
pet dog ZEBRA snails horse fox

2. Simple object access protocol!!
•

3. Its also programming. 54321 is the question and 12345 is the answer. Simple C Program!!

4. ? what........any hints that are actually helpful? lol

5. Its easy to point out how easy a riddle is when you know the answer. I bet if I put a bunch of letters together that you didn't know the pattern for it would seem impossible to you....
•

6. i give up, goodnight

7. Just dug up the old thread, went through over 400 pages of posts until someone figured out the puzzle there but I couldn't find where the solution was posted and how they found it..I have earned this sleep that I'm about to enjoy. Someone please solve this puzzle so my brain can relax.

8. Going to sleep...... wish this is was easier!

9. Ive been up all night and cant figure it out lol

10. Originally Posted by ayanes35
What's going on in here?

(Woo first AM post!)
I don't think anyone got to welcome you. So welcome to AM... Lots of good fun and people here.

11. The answer is: there is no answer!

12. well it is not a Ceasar cipher...

13. Let me grab my secret decoder ring...Drink Ovaltine?!

14. Originally Posted by Vitruvian
Mini Contest #1aka The warm-up puzzle... Enough to get you thinking, easy enough to be solved:

rlntN.et i. otc.o he.fti hswgNe oee prtocaksvor! ant arty !e Nb ssoo ttwtF a titrtlrhthesrea tedto a! fpd w e. eNr P'es orooFsevnit a r artstl othlJ i uptswmoo aps erstdnmt oteaA idrFsr tToeu!E p!Rwp,! ia !tnrl!hsae!e gt! ar'!w as!ibp !nohg!nt e!eti
Internet is to cop hefty swings o'er pro tax viewer! Ant art be nub so tweet a turtle this real today! For we impress our roof sent a rattle sloth up to swoon apartments of tea aids first toe! Prop! Ya! Internal sales get our wasabi gnocchi elite!

15. uhh.. yeah dude i'm just a dumb meat head. I'm not so sure about these puzzles.

16. Originally Posted by superbeast668
uhh.. yeah dude i'm just a dumb meat head. I'm not so sure about these puzzles.
Right? If it was 2 plates on each side + bar = im sure we would have gotten the answer by now

17. Originally Posted by Marms
Right? It it was 2 plates on each side + bar = im sure we would have gotten the answer by now
yeah... warm up!

18. It is solvable guys. Keep trying........hmmm.....I don't always read a sentence across the page, sometimes up? sometimes down?

jdg76
Team APPNUT

19. Originally Posted by jdg76
It is solvable guys. Keep trying........hmmm.....I don't always read a sentence across the page, sometimes up? sometimes down?

jdg76
Team APPNUT
I'm trying so hard! N I gotta leave for the day soon so, boo

20. I just emailed a copy over to Nick and his crew, hope they call me soon!!

21. All right guys I'll let your minds rest for a bit and.......

START A NEW PROMO !!!!

First person to guess what I am wins !!!!!!!

Let's see who is awake this early??

I'll check in after awhile and see who the winner is.

22. Resveratrol?

23. Vitimin C?

24. Antioxident

25. Originally Posted by jdg76
All right guys I'll let your minds rest for a bit and.......

START A NEW PROMO !!!!

First person to guess what I am wins !!!!!!!

Let's see who is awake this early??

<img src="http://anabolicminds.com/forum/attachment.php?attachmentid=61 149"/>

I'll check in after awhile and see who the winner is.
Propane ?

26. Glucose

27. Originally Posted by AaronJP1
Propane ?
The sad thing is that I watch so much King of the Hill that I know that propane's chemical makeup is c3h8..

28. Hydrogen Peroxide

29. Silly Putty!! Lol

30. It's a steroid. That double bonded oxygen at the bottom is the only difference from testosterone. Haven't figured it out yet though.

•