The Zebra Puzzle

Part of the answer must be they all drink water. Even the animals. I hope this isn't an aggravating answer where someone argues they only drink some other beverage, because some people do claim to not drink water. Because then the answer might be only the animals.

So far, I have gotten that the Norwegian drinks water (and lives in the yellow house, and smokes Kools - still working on the pet).

P.S. I assume the zebra ends up belonging to the one that doesn't own any other named pet? Just a guess I didn't work the puzzle.

House 1: Norwegian, Yellow, Water, Kools, Fox

House 2: Ukrainian, Blue, Tea, Chesterfield, Horse

House 3: Englishman, Red, Milk, Old Gold, Snails

House 4: Spaniard, Ivory, Orange Juice, Lucky Strike, Dog

House 5: Japanese, Green, Coffee, Parliament, Zebra

House 1: +NORWEGIAN +YELLOW +KOOLS +WATER +FOX
House 2: +BLUE +HORSE + UKRANIAN + TEA + CHESTERFIELD
House 3: +MILK
House 4:
House 5:

Englishman: +REDHOUSE (NOT WATER) (NOT KOOLS)
Spaniard: +DOG (NOT WATER) (NOT KOOLS) (NOT YELLOW)
Ukranian: +TEA (NOT KOOLS) (NOT YELLOW)
Norwegian: +HOUSE 1 ///BLUENEXTDOOR +YELLOWHOUSE (NOT Coffee) (NOT Milk) (NOT Tea)
Japanese: +PARLIAMENTS (NOT YELLOW) (NOT WATER)

Red House: +ENGLISHMAN
Green House: +COFFEE +RIGHTOFIVORYHOUSE (NOT "House 1") (NOT Ukranian) (NOT "House 3") (NOT Norweigian) (NOT Englishman) ("NOT House 2")
Blue House: ///NORWEGIANNEXTDOOR
Ivory House: +LEFTOFGREENHOUSE (Not "House 5")
Yellow House: +HOUSE1

Old Gold: +SNAILS
Kools: +YELLOWHOUSE ///NEXTTOHORSEHOUSE
Chesterfields: ///NEXTTOFOXHOUSE
Parliaments: +JAPANESE
Lucky Strike: +ORANGEJUICE

Fox: ///CHESTERFIELDNEXTDOOR
Horse: ///KOOLSNEXTDOOR
Zebra: Don't Bother***
Dog: +SPANIARD
Snails: +OLDGOLD

Milk: +HOUSE3
Orange Juice: +LUCKYSTRIKE
Tea: +UKRANIAN
Coffee: +GREENHOUSE
Water: Don't Bother***

NOTE KEYS:

+---The plus sign means this definitely goes with this.

(NOT)---This means this does not go with this.

///---Slashes tell you about something closely related. These are usually secretly the most helpful.

***You don't bother with these because you are told nothing about them other than they exist.

EARLY SOLUTIONS

1.) We are told that the Norwegian lives in the first house (10) and next to the blue house (15), so the second house must be the blue house.

2.) We know that the Green House drinks coffee and is NOT the first house, because the Norwegian lives there. We also know that it is not the first house, because the first house is not to the right of anything. From 1.), we know that the second house IS blue, so the green house cannot be the blue house. We KNOW that the green house MUST be to the right of the ivory house, so it cannot be HOUSE 3, or it would be to the right of the blue house.

Therefore, the Green House MUST either be House 4 or House 5

3.) We KNOW that House 1 cannot be the Ivory House because the house to its right is Blue and the Green House must be to the right of the Ivory House. We KNOW that House 1 cannot be Red because the Norwegian lives there and Red MUST belong to the Englishman. Therefore, House 1 is NOT Red, Ivory, Green, or Blue and MUST be Yellow.

4.) We KNOW that the Norwegian does NOT drink coffee, because coffee is drunk in the Green House. We KNOW that the Norwegian does not drink Milk, because milk is drunk in the third house. We KNOW that the Norwegian does not drink Tea because the Ukranian drinks Tea. The Norwegian must drink either water or orange juice.

5.) We KNOW that House 1 is the Norwegian and is Yellow, thus, House 1 MUST smoke Kools.

6.) The smoker of Lucky Strikes drinks orange juice, House 1 smokes Kools...House 1 is the Norwegian, the Norwegian does NOT drink coffee, milk or tea...now we know he also doesn't drink orange juice, so House 1 CAN ONLY drink water.

7.) Because Kools ARE smoked in the house next to the horse, and House 1 smokes the Kools, the Horse MUST be in House 2.

8.) The Green House drinks Coffee and MUST be House 4 or House 5. House 3 drinks milk.

9.) House 3 does NOT smoke Kools because House 1 does. House 3 does NOT smoke Lucky Strikes because that person drinks orange juice. Here are the possibilities for House 3:

Smokes Old Gold + Owns Snails
Smokes Parliaments and is Japanese
Smokes Chesterfields and lives next to a man with a fox---House #4 would have a fox, in this case.

10.) The Ukranian drinks tea, so CANNOT live in House 3 and Does Not live in House 1, because that is the Norwegian. The Ukranian does NOT smoke Kools because House 1 smokes those. The Ukranian does NOT smoke Parliaments because he is not Japanese. The Ukranian does NOT smoke Lucky Strikes because he does not drink orange juice. Therefore, the possibilities:

The Ukranian smokes Old Gold and owns snails.
Smokes Chesterfields and lives next to a house with a fox.

11.) IF the Ukranian smokes Chesterfields, then he MUST live in House #2 and a Fox MUST live in House #1 or House #3.

12.) The Ukranian can NOT live in a Green House because he drinks tea and the Green House drinks coffee.

13.) (LEAP OF FAITH) Clue #15 references the Norwegian living next to the blue house, which is House #2. Clue #11 is the only other clue that cares about what a neighbor is doing that doesn't involve house color and answers the only thing we don't know about House #1, if true. SEE #14 and #15...

14.) House 1 does NOT have a Horse, because a Horse lives in House 2. House 1 is NOT the Spaniard, so does not have a dog. House 1 does NOT smoke Old Gold, so does not keep Snails.

House 1 either has a fox or a zebra.

15.) (LEAP OF FAITH) A clue for House 1 refers to House 2. If House 1 has a fox, then that would mean a clue for House 2 would be referring back to House 1. More than that, ZEBRA and WATER are the only two items for which we are not provided any facts, but we already know WATER goes to House 1 because nothing else can go there, so would WATER and ZEBRA really both go to House 1? Doubtful.

This would also complete Houses 1 and 2.

Also, can go back and change this if it doesn't work out...so put *** as a point of uncertainty.

16.) The remaining three houses are red, ivory and green. The green house MUST NOT be the third house, because it must go to the right of the ivory house. Here are the possibilities:

Red-Ivory-Green

Ivory-Green-Red

TAKE AN INVENTORY OF REMAINING ITEMS AND RESTART

House 1: +NORWEGIAN +YELLOW +KOOLS +WATER +FOX
House 2: +BLUE +HORSE + UKRANIAN + TEA + CHESTERFIELD
House 3: +MILK +RED +ENGLISHMAN + OLD GOLD +SNAILS
House 4: +SPANIARD +DOG +IVORY +ORANGE JUICE +LUCKY STRIKES
House 5: +JAPANESE +PARLIAMENTS +COFFEE +GREEN +ZEBRA

Smokes:
Parliament +JAPANESE
Lucky Strike (NOTJAPANESE)
Old Gold (NOTJAPANESE) + SNAILS

Houses:
House 3 (NOT GREEN) (NOT SPANIARD)
House 4
House 5 (NOT IVORY)

Colors:
Red +ENGLISHMAN
Green (NOT HOUSE 3) +COFFEE
Ivory (NOT HOUSE 5)

People:
Japanese +PARLIAMENT
Englishman +RED HOUSE
Spaniard +DOG (NOT HOUSE 3) +LUCKY STRIKES + ORANGE JUICE (NOT RED) (NOT GREEN) +IVORY +HOUSE4

Pets:
Dog +SPANIARD
Snails +OLDGOLD
Zebra Don't Bother

Drinks:
Milk: +HOUSE 3
Orange Juice: +LUCKY STRIKES +SPANIARD
Coffee: +GREENHOUSE

17.) House 3 drinks milk. The Green House drinks coffee. House 3 cannot be green, but we already knew that. House 3 does NOT smoke Lucky Strikes because that is what Orange Juice smokes. Possibilities for House 3:

+MILK
---Is Ivory or Red
-Smokes Parliaments and is Japanese or smokes Old Gold and has snails.

FACT: The Spaniard is NOT Japanese. The Spaniard does NOT have snails because he has a dog. The Spaniard CANNOT live in House 3 because he does not satisfy either of the possible conditions.

18.) The Spaniard CANNOT smoke Old Gold because he has a dog. The Spaniard CANNOT smoke Parliaments because he is not Japanese.

19.) The Spaniard MUST smoke Lucky Strikes.

20.) The Spaniard lives either in House 4 or House 5.

21.) The Spaniard cannot live in a green house, because he drinks Orange Juice and smokes Lucky Strikes. The Green House drinks Coffee. The Green House CAN NOT be House 3. The Spaniard CAN NOT be House 3. The Spaniard MUST live in House 4 which MUST be Ivory.

22.) House 3 MUST be the Red House and the Englishman lives in the red house.

23.) The Japanese smokes Parliaments and the only other cigarette brand is Old Gold, so the Englishman who lives in Red House 3 must smoke Old Gold and have Snails.

24.) The Japanese smokes Parliaments and lives in House 5 Green and must have a zebra because there are no other animals.

The Ukranian smokes Old Gold and has Snails

I respect the method of proving by contradiction. I've done other puzzles that way. However, with this one, I tried to add to the full solution one bit of information at a time. See next spoiler tag for how I started.

I created ten matrices for each combination of the way to match any two items. Here is how it looked blank.


There were side notes that pertained to the order of the houses.

Then I simply filled it in, slowly. Most of it was simply this logic, over and over:

The Wizard lives in a red house
Mission lives in a blue house
Wizard has a horse.
Mission drinks milk.

We could then say the horse does not live with the milk drinker.

1, Norwegian, Yellow, Water, Fox, Kool
2, Ukrainian, Blue, Tea, Horse, Chesterfield
3, English, Red, Milk, Snail, Old Gold
4, Spaniard, Ivory, Orange Juice, Dog, Lucky Strike
5, Japan, Green, Coffee, Zebra, Parliament

Clue 6: The green house is immediately to the right of the ivory house.
This means that the green house is not 1, and the ivory house is not 5; since the blue house is 2 (by clues 10 and 15), the ivory house cannot be 1, and the green house cannot be 3. This means the ivory and green houses are either 3 and 4 or 4 and 5, so house 4 cannot be red or yellow (we already know it is not blue).

Clue 12: Kools are smoked in the house next to the house where the horse is kept.
You can determine early on that Kools are smoked in 1, so Horse must be in 2.

Clue 11: The man who smokes Chesterfields lives in the house next to the man with the fox.
When you determine where Chesterfields are smoked, you can eliminate Fox from the three locations not next to that one.