1. There are five houses of different colors in a street. Every house is inhabited by people of different nationalities. Everyone smokes different cigarettes, drinks different drinks and keeps different pets.
The English live in a red house.
3. Spaniards have dogs.
People who live in green houses drink coffee.
5. Ukrainians drink tea
6. The green house is on the right of the milky white house.
7. Take the last romantic paragraph to raise snails.
8. Mint smokers live in a yellow house.
9. People who live in the middle house drink milk.
10. Norwegians live in the first house.
1 1. People who smoke chesterfield live next door to people who keep foxes.
12. People who smoke mint cigarettes live with people who keep horses.
13. People who smoke lottery tickets drink orange juice.
14. Japanese cigarettes are supreme.
15. The Norwegian lives next door to the blue house.
So, who drinks water? Who keeps zebras? The earliest known source of this puzzle is the international edition of Life magazine (1962 17 February). On March 25th, 1963, the magazine published the answer and the list of hundreds of solvers around the world. There are countless variants of this puzzle, one of which is "which country raises fish" which is widely circulated on the Internet. People are afraid of being famous and pigs are afraid of being strong. This complicated puzzle is inexplicably attributed to Einstein, the smartest brain in the 20th century. This question was made up by Einstein when he was young and widely circulated, so this puzzle is often called "Einstein's mystery". But some people say that the author is actually lewis carroll. Well, let's leave these groupies alone, because there is no evidence that the author is any of them now. Besides, the cigarette brand in the puzzle did not appear when Einstein was a child.
Pirate puzzle (pirate puzzle)
This is a popular puzzle, which contains popular elements such as piracy, money and democracy. The story goes like this: There are five rational pirates A, B, C, D and E, and they got 100 gold coins, and they want to share them. There are different levels in the pirate world. The ranking of these five pirates is as follows: A > B& gt；; C>D>e. The stolen goods sharing system is also very democratic: first, the pirates with the highest level put forward the distribution plan, and then all pirates (including the proposer) vote to decide whether to accept it or not. If more than half of the people agree, the proposal will be passed, otherwise the sponsor will be thrown overboard, and the pirate with the second highest level will continue to propose, and so on. The factors considered by pirates are: one is to survive, the other is to get the most money; If they get the same money anyway, they are more willing to harm others. For A, the best scheme is as follows: A gets 98, B gets 0, C gets 1, D gets 0, and E gets 1. The answer is almost beyond everyone's expectation. Generally, we will give the other four pirates gold coins to save our lives through the proposal, but the answer tells us that greed is better. The mystery of pirates first appeared in the May issue of Scientific American, 1999. This article entitled "The Puzzlement of Pirates" was written by ian stewart, a British mathematician. He analyzed the problem in detail and expanded the number of pirates to n, and got a very interesting conclusion. He heard about this difficult problem from Stephen M. Moderow. It is speculated that this puzzle has been circulating for at least 10 years. This is a classic puzzle in every way. This interesting question will be mentioned in any game theory course.
Where is the dollar? Three travelers checked into a hotel, and the boss accepted their 30 yuan at the price of 10 yuan per person. Later, the boss decided to give them some discounts and gave the waiter 5 yuan to return to the passengers. It is obvious that the boss can't do math and gave a number that can't be divisible by 3. The clever waiter secretly hid 2 yuan himself, and then returned 1 yuan to every passenger. Now every customer has given a discount of 1 yuan, so everyone has given it to 9 yuan, one to 27 yuan, and 2 yuan and the waiter are 29 yuan. But at first they gave the boss, 30 yuan. Where's the other dollar? Almost everyone will be fooled after reading it. After reading it, they still feel extremely correct. After reading it, many careless people don't understand until they see the answer. I didn't expect it to be so simple. A search on the Internet titled "Interesting Mathematics in Grade One" greatly affected my self-esteem.
Where did this puzzle originally come from? The most popular saying on China Internet is that this puzzle comes from a "New Zealand interview question", and its authenticity needs to be identified by the rumor mongers. In fact, the history of this problem may be much longer than you think. At least it can be traced back to the mathematics textbook 1949 published by the University of California, and the earliest source is probably unknown. This paradox is successful because 27+2 = 29 and 30 are almost the same (if the difference is too big, it will inevitably arouse suspicion), and the imaginative audience has not figured out what these two things add up to, and began to extrapolate. Who knows that this formula itself is wrong, 2 yuan has been included in 27 yuan, and 27-2 = 25 is the boss's money, and there is no shortage. Later, people gave a special answer to this puzzle and laughed at their original mistake: "A few months later, two of them stayed in this hotel again, and the boss charged each person 10 yuan, a *** 20 yuan. Later, he wanted to give passengers a discount, and it was 5 yuan; Then the waiter, but this time deducted 3 yuan and gave it to the passenger 1 yuan. Now each passenger has paid 9 yuan, which adds up to 18 yuan, plus the waiter's 3 yuan, which is * * * 2 1 yuan. You see, the missing 1 yuan is here. " .
An impossible puzzle.
There are two unequal integers x and y, both greater than 1 and less than 100. Mathematician Mr. He knows the sum of these two numbers, and mathematician Mr. Ji knows the product of these two numbers. They have the following conversation:
Mr. Ji: I don't know what X and Y are respectively.
Mr. He: I know you don't know.
Mr. Ji: I know now.
Mr. He: You know, then I know. So, what are x and y? Now you know why this is called an impossible puzzle, because it seems impossible for us to solve X and Y just by looking at these words of "nonsense". 1969, the Dutch mathematician Hans Freudenthal published this difficult problem, which was called "Freudenthal problem" at that time. It was not until 1976 that David Sprouse published the English version of this question in Mathematics magazine. In 1979, martin gardner once again mentioned this difficult problem in his column, calling it "impossible difficult problem". Since then, this problem has become a hot topic. It has countless varieties and is widely circulated. The title description seems simple, but the answer is not. Edsger W. Dijkstra, the Turing Prize winner, said that he solved another version of this problem in 1978. Before, he tried to solve it in his mind countless times, but fell asleep repeatedly. Finally, on a sleepless night, it took him six hours to solve the problem in his mind without using a pen and paper. In the process of proof, he also used Goldbach conjecture a little.
The puzzle of the missing square puzzle needs no introduction, and the picture has explained everything. A small cell is missing from the triangle above. Where did it go? Martin gardner said that it was invented by Paul Curry, an amateur magician in new york, in 1953, so it is also called Curry Paradox. All puzzles similar to Kerry's paradox are called "anatomical paradox". Martin gardner introduced another similar paradox in his Mathematics Magic and Mystery, called Hooper's Paradox, which was published by mathematician William Hooper in 1774. Later, after investigation by Professor Douglas Rogers, Hooper's paradox actually originated from the anthology "New Edition of Physics and Mathematics" published by French writer Eddm Giles Submarine Pingdingshan from 1769 to 1770.
The most difficult logical puzzle in history.
There are three elves, one only tells the truth, one only tells lies, and the other randomly tells the truth or lies. You can ask these three elves three true or false questions, and you can ask anyone at a time. You can ask the next question according to the answer to the previous question. Your task is to judge their identity. It's a pity that they can understand you, but they answer in their dialects-da and ja. You don't know which is right and which is wrong. So, what three questions should you ask? This title party is attributed to the logician George Stephen Blos of MIT. 1996, he published an article of the same name in Harvard Philosophy Review, in which he said that this puzzle was invented by American mathematician Raymond Smolian. This puzzle seems a bit circuitous, but in fact it's not that complicated. Smolian once put forward a simplified version of this question, Knight and Rogue, in which there are no emotionally unstable third parties, and you can understand what they said. Later, some people thought it was not difficult enough, so they added the condition that "you don't understand them". This man is john mccarthy, the Turing Prize winner. Later, a third party was added to the title, which was regarded as "the most difficult logical puzzle in history". These related puzzles can be seen in Smolian's What's the Name of the Book and The Mystery of Scheherazade.
Suppose you take part in a TV game show. There are three doors at the performance site, one of which is behind a car and the other two are behind a goat. The host lets you choose one of the doors. Suppose you choose gate one. The host deliberately opens another door, such as the third door, so that you can see the goat behind the third door. Then the host asked you, "Do you want to change your choice and change to Gate 2?" What will you do at this time? This game first appeared in the American TV game show "Let's Make a Deal". 1975, Professor Steve Sellven published an article in American Statistician, calling this issue "Monty Hall Problem" because the name of the proposer was Monty Hall. Marilyn vos savant, recognized by Guinness World Records as the highest IQ human being, opened a column called "Ask Marilyn" in Cruise magazine to answer readers' questions.
In 1990, a reader of Craig F. Whitaker sent this question to this column, and Marilyn answered it like this: "The winning probability of sticking to the first door is 1/3, but the winning probability of switching to the second door is 2/3, so you should switch to another door. Imagine the following situation, there are 6.5438+0 million doors. After you choose the first door, the owner who knows the inside story opens all the other doors except the second door. You will definitely change your choice decisively, won't you? " After this solution was published, it caused great controversy because it greatly violated people's intuition. Even many university doctors wrote to "correct" her mistake on the grounds that after the host opened a door, there was only one car and one sheep left, and the probability obviously became 1/2. They urged Marilyn to "admit her mistake", and some even said that she was "worried about the future of America". These records are still on Marilyn's website. You might as well go and see how many doctors have stumbled.