Everyone knows Einstein, and everyone knows that Einstein is recognized as one of the people with super high IQ. The word genius is customized for Einstein, such as mass-energy equation, photon hypothesis/photoelectric effect, great promotion to quantum physics, and special \ general relativity. . . . . . These achievements are like bright stars in the night sky, making Einstein a "great man of the century". As a result, such as famous sayings of celebrities, excellent stories of celebrities as children, and those who have or have not been placed on Einstein. Let's not talk about these specious things. Everyone must have heard of "Einstein's IQ test", claiming that only 2% of people can do it. The topic is as follows:

A. On a street, there are five houses painted in five colors. ?

B. People of different nationalities live in each room?

C. Everyone drinks different drinks, smokes different brands of cigarettes and keeps different pets?

the question is: who keeps fish? ?

known:?

1. Do British people live in red houses?

2. Do Swedes have dogs?

3. Do Danes drink tea?

4. The green house is on the left of the white house?

5. Does the owner of the green house drink coffee?

6. Do people who smoke Pall Mall keep birds?

7. Does the owner of the yellow house smoke Dunhill cigarettes?

8. Do people who live in the middle house drink milk?

9. Norwegians live in the first room

1. Blends smokers live next door to cat owners?

11. Does the horse owner live next door to the Dunhill smoker?

12. Do people who smoke Blue Master drink beer?

13. Do Germans smoke Prince cigarettes?

14. The Norwegian lives next door to the blue house?

15. People who smoke Blends cigarettes have a neighbor who drinks water.

First announce the answer: Germans raise fish.

The derivation process is recorded, and before publication, I would like to remind you:

Independent thinking can make you smarter! Independent thinking can make you smarter! Independent thinking can make you smarter! Important things must be said three times.

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * gorgeous.

Deduction process:

First, read through all the conditions, and find that everyone has the following attributes: nationality, house color, house location, pet, drink and cigarette, and one * * * six attributes

We call the above known contents "conditions" 1-15; Call all the following reasoning steps and intermediate results "inference"

A. From condition 9+condition 14, it can be inferred that the second house is blue;

B. Condition 5+Condition 8, it can be inferred that the house in the middle must not be green. Combined with inference A+Condition 4, it can be known that the fourth room is green and the fifth room is white;

C. From Condition 1+Inference A+Inference B+Condition 9, it can be known that the British live in the middle house (the third room), and the third room is red;

condition 1+inference A => English people must not live in the second house

Inference B => English people must not live in the fourth and fifth houses

Condition 9 => English people must not live in the first house

To sum up: English people live in the third house; According to condition 1, the third room is red

D. From inference A, B and C, it can be inferred that ※ Important conclusion

The first room: yellow second room: blue third room: red fourth room: green fifth room: white

E. From inference D+condition 14, it can be inferred that the Norwegian lives in the first yellow house. It can be inferred that Norwegians smoke Dunhill cigarettes

g. From inference F+condition 11, it can be inferred that people in the blue room raise horses

So far, we can give a preliminary inference summary:

The following inference needs to be assumed.

H. condition 12 is crucial, because beer and blue master cigarettes must appear in pairs. See the above table, it can be seen that only blue houses and white houses can meet condition 12, so we assume that X: people in blue houses smoke blue master cigarettes and drink beer

At this time, we add condition 3: Danes drink tea, because the first house is Norwegian, while the second one is beer (the above assumption X), the third one is milk and the fourth one is coffee, so at this time, only the white house can meet condition 3. Based on hypothesis X, Danes in white houses like to drink tea

here, so we can infer that the drink in the first room is water

at this time, there is a contradiction: condition 15 is not satisfied, because the drinker has only one next door and smokes blue master cigarettes

Therefore, we can be sure that hypothesis X is not valid; That is to say, it can be inferred that people in the blue house must not smoke blue master cigarettes and drink beer

i. Based on H's last inference, we said that only blue houses and white houses can meet condition 12, and the blue house has been excluded, then it is inferred that people in the white house smoke blue master cigarettes and drink beer

j. Based on inference I and condition 3, it can be inferred that the blue house is Danish. Drinking tea

K. Based on the above table, condition 13, because we have confirmed the nationality of the first three houses, only the green house and the white house may be German, and because the owner of the white house smokes blue master cigarettes, it can be inferred that the green house is German and smokes price cigarettes

L. Based on the above inference, it is inferred from condition 2 that the owner of the white house is Swedish and keeps a dog

. We still have conditions 6, 1 and 15 that are not used, but because condition 6 clearly has two attributes, and conditions 1 and 15, although they have two attributes, belong to the "next door", that is, they are not the attributes of the same person, and the scope of information restriction is not as good as that of condition 6, so we continue from condition 6.

m. Looking at all the conclusions so far, it is concluded that only British people with red houses can exclude yellow, green and white houses through cigarettes, while blue houses can be excluded through pets. Therefore, it is presumed that British people with red houses smoke Pall Mall cigarettes and keep birds

n. The rest of the reasoning is logical: people with blue houses smoke Blends cigarettes; Condition 1: Norwegians in yellow houses will keep cats;

At this point, we can get the final result: Germans are fish farmers.

Let's make a final check with the last condition to see if there is any conflict: Norwegians like drinking water, and there is no conflict.

finally, explain why the assumption in step h uses condition 12 instead of condition 6, both of which require both attributes to be met at the same time. It is because when going to step H, the determined attributes of beverage+cigarette are more than those of pet+cigarette, which means that we can use more known conditions at the same time when using condition 12. This is also a basic principle when making decisions: use branches with more known quantities as much as possible to make decisions, and avoid branches with more unknown quantities as much as possible.

that's the derivation of this topic.