There is an intellectual problem in this. Very interesting
Example 1: You let the workers work for you for 7 days, and the workers' reward is a gold bar. Gold bars are divided into seven consecutive parts. At the end of each day, you must give them some gold bars. If you are only allowed to break the gold bars twice, how can you pay the workers?
Xiao Pu (now working in minimally invasive surgery, I met this question last year): This question is relatively simple compared with other minimally invasive questions, but it still makes my head bigger. That's how I did the problem. If it is broken twice, it will be divided into three parts. I divided the gold bars into three parts: 1/7, 2/7 and 4/7. In this way, I can give it to him on 1 that day1/7; The next day, I gave him 2/7 to get back1/7; On the third day, I will give him 1/7, plus the original 2/7 is 3/7; On the fourth day, I gave him 4/7 gold bars and asked him to find out 1/7 and 2/7 gold bars. On the fifth day, give him1/7; The sixth day is the same as the second day; 1/7 restored him on the 7th day.
Example 2: Now Xiaoming's family has crossed a bridge. It's dark when crossing the bridge, so there must be a light. Now it takes 1 second for Xiaoming to cross the bridge, 3 seconds for Xiaoming's brother, 6 seconds for Xiaoming's father, 8 seconds for Xiaoming's mother and 12 seconds for Xiaoming's grandfather. At most two people can cross the bridge at a time. The speed of crossing the bridge depends on the slowest one. The light turns on for 30 seconds and then goes out. Ask Xiaoming how to cross the bridge.
Reference answer: This puzzle is actually to examine the ability of candidates to solve problems under restricted conditions. Specific to this topic, many people often think that Xiao Ming should go into battle lightly, which saves the most time, but in the end he can't find a solution. But in another way of thinking, we can decide who will come and go according to the specific situation, as long as we make some slight changes: the first step, Xiaoming crosses the bridge with his brother and Xiaoming comes back, which takes 4 seconds; In the second step, Xiaoming crossed the river with his father and his younger brother came back, which took 9 seconds. The third step, mom and grandpa cross the river, and Xiaoming comes back, which takes 13 seconds; Finally, Xiao Ming and his younger brother crossed the river in 4 seconds, with a total time of 30 seconds. How thrilling!
Expert's point of view: This kind of topic often appears in the recruitment interview of multinational enterprises, which plays an extremely obvious role in examining a person's thinking mode and ability to change thinking mode. According to some studies, this ability is often closely related to the tension and innovation at work. Therefore, when answering these questions, we must break through the mindset, try our best to consider the problem from different angles, constantly think backwards and empathize, and connect the question with the familiar scene to avoid confusion.
Now, let's start a question to test you:
Puzzle: Guess the card.
Introduction: This is a classic and interesting logical question.
Detailed introduction:
Mr. S, Mr. P and Mr. Q know that there are 16 playing cards in the desk drawer: hearts A and Q, 4 spades J, 8, 4, 2, 7, 3 flowers K, Q, 5, 4 and 6 diamonds A and 5. Professor John chooses a card from 16 card, tells Mr. P the number of points in this card, and tells Mr. Q the color of this card. At this time, Professor John asked Mr. P and Mr. Q: Can you infer what this card is from the known points or colors? So, Mr. S heard the following conversation: Mr. P: I don't know this card.
Mr q: I know you don't know this card.
Sir: Now I know this card.
Mr. Q: I know that, too.
After listening to the above conversation, Mr. S thought about it and correctly deduced what this card was.
Excuse me: What kind of card is this?
Classic puzzle set
Introduction: See how much you know?
Detailed introduction:
1. A manager has three daughters, and their ages add up to 13. The ages of the three daughters add up to the manager's own age. A subordinate already knows the manager's age, but still can't determine the age of the manager's three daughters. At this time, the manager said that only one daughter's hair was black, and then the subordinates knew the age of the manager's three daughters. What are the ages of the three daughters? Why?
3 people went to a hotel and stayed in 3 rooms. The price of each room is $65,438+00, so they pay the boss $30. The next day, the boss thought that $25 was only enough for three rooms, so he asked my brother to return $5 to three guests. Unexpectedly, my brother was insatiable, and only returned 1 USD each, and secretly took it away by himself. But at the beginning, the three of them paid 30 dollars, so 1 dollar?
There are two blind people. They all bought two pairs of black socks and two pairs of white socks. Eight pairs of socks are made of the same cloth, the same size, and each pair of socks is connected with trademark paper. Two blind people accidentally mixed up eight pairs of socks. How can each of them get back two pairs of black socks and two pairs of white socks?
4. One train leaves Los Angeles for new york at the speed of 15km per hour, and another train leaves new york for Los Angeles at the speed of 20km per hour. If a bird starts from two trains at a speed of 30 kilometers per hour, starts from Los Angeles, meets another train and returns, and flies back and forth in turn until the two trains meet, how long does the bird fly?
You have two jars, 50 red marbles and 50 blue marbles. Choose a jar at random and put a marble in the jar at random. How can you give red marbles the best chance? What is the exact probability of getting the red ball in your plan?
Classic Interview Questions: Interesting Intelligence Questions of Foreign Enterprises
6. You have four jars containing pills. Each pill has a certain weight. The contaminated pill is the uncontaminated weight+1. You only weigh it once. How do you know which jar is polluted?
7. For a batch of lights numbered 1 ~ 100, all the switches are turned up (turned on), and the following operations are done: always turn the switches in the opposite direction once in multiples of 1; A multiple of 2 toggles the switch in the opposite direction again; A multiple of 3 turns the switch in the opposite direction again ... Q: Finally, the number of lights in the off state.
8. Imagine yourself in front of a mirror. Excuse me, why can the image in the mirror be upside down, but not upside down?
9. A group of people held a dance, each wearing a hat. There are only two kinds of hats, black and white, and there is at least one kind of black. Everyone can see the color of other people's hats, but not their own. The host first shows you what hats others are wearing, and then turns off the lights. If someone thinks he is wearing a black hat, he will slap himself in the face. The first time I turned off the lights, there was no sound. So I turned on the light again and everyone watched it again. When I turned off the light, it was still silent. I didn't get a slap in the face until I turned off the light for the third time. How many people are wearing black hats?
10, two rings with radii of 1 and 2 respectively. The small circle goes around the big circle. How many times does the small circle turn by itself? If it is outside the big circle, how many times does the small circle turn by itself?
1 1, 1 Yuan for a bottle of soda. After drinking two empty bottles, change one bottle of soda. Q: You have 20 yuan money. How many bottles of soda can you drink at most?
Determination of hat color problem
Introduction: This is a classic and interesting logical question.
Detailed introduction:
There are three red hats, four black hats and five white hats. Let 10 people stand in a row from short to high, each wearing a hat. Everyone can't see the color of his hat, but he can only see the color of the hat of the person standing in front. So the last person can see the color of the hats on the heads of the nine people in front, while the first person can't see anyone's hats. Now, start with the last person and ask him if he knows the color of the hat he is wearing. If he says no, keep asking the person in front. Suppose the person in front must know that he is wearing a black hat. Why?
Call it the apple problem
Introduction: Not a brain teaser. Let's think about it.
Detailed introduction:
10 box, with 10 apples per box, including 9 apples per box and the rest 1 kg. A box containing 9 pairs/piece can be found only by using the balance once.
The survival of prisoners
Introduction: A puzzle that really stumbles hundreds of millions of people is an interview question of Microsoft.
Detailed introduction:
Five prisoners, according to 1-5, caught mung beans in sacks containing 100 mung beans. It is stipulated that everyone should catch at least one, and those who catch at most and at least should be put to death. And they can't communicate with each other, but when they catch, they can find out the remaining number of beans. Ask them who has the best chance of survival. Tip:
1, are very smart people.
Their principle is to save people first, and then kill more people.
3, 100 don't have to finish it all.
4. If there is any duplication, it will be regarded as the largest or smallest and executed together.
Table tennis problem
Introduction: This topic is transformed from China folk website, which has certain difficulty.
Detailed introduction:
Suppose there are 100 ping-pong balls arranged together, and two people take turns to put the balls in their pockets. The winner is the person who can get the100th table tennis. The condition is: the person who holds the ball must take at least 1 at a time and not more than 5 at most. Q: If you are the first person to take the ball, how many should you take? How can I take it in the future to ensure that you can get the100th table tennis?
The speed of goats
Introduction: None
Detailed introduction:
Professor Lum said: "I once witnessed a duel between two goats, which led to an interesting math problem." One of my neighbors has a goat, which weighs 54 pounds. It has been king in the nearby mountains for several seasons. Later, a good-hearted man introduced a new goat, which was 3 Jin heavier than it. At first, they lived in harmony with each other. But one day, the lighter goat stood at the top of the steep mountain road and pounced on its competitor. Competitors stand on the mound to meet the challenge, and challengers obviously have an absolute advantage. Unfortunately, both goats died because of the violent collision.
Now let's talk about the wonders of this topic. George abercromby is proficient in raising goats and has written a book. He said: "Through repeated experiments, I found that the momentum is equivalent to the impact of a 30-pound weight falling from a height of 20 feet, just enough to break the goat's skull and kill it." If he is right, how fast must the two goats approach each other before smashing their skulls? Can you work it out?
The problem of restaurant proprietress
Introduction: None
Detailed introduction:
It is said that someone gave the proprietress of a restaurant a difficult problem: this person clearly knew that there were only two spoons in the shop, which could scoop 7 taels and 1 1 taels respectively, but forced the proprietress to sell him 2 taels of wine. Smart proprietress is also unambiguous. She used these two spoons to hold the wine, turned it upside down and actually measured out 2 ounces of wine. Can you be smart?
A problem about aircraft refueling.
Introduction: None
Detailed introduction:
It is known that each plane has only one fuel tank, and planes can refuel each other (note that there is no tanker). A tank of oil can make an airplane fly half a circle around the earth. Question: How many planes must be dispatched to make at least one plane fly around the earth and return to the airport after take-off? All planes take off from the same airport and must return to the airport safely. It is not allowed to land midway, and there is no airport in the middle.
difficult problem
Introduction: This kind of question is more difficult. If you can't get the answer, it doesn't mean anything. If you think of a solution to the problem, the answer will come out soon. If you can't think of ideas, then … don't try to think of them.
Detailed introduction:
1. You let the workers work for you for 7 days, and the reward is a gold bar. This gold bar is divided into seven connected parts, and you must give them a gold bar at the end of each day. If you were only allowed to break the gold bars twice, how would you pay the workers? 2. One train leaves Beijing at a speed of 15km/h and goes straight to Guangzhou, and the other train leaves Guangzhou for Beijing at a speed of 20 km/h. If a bird sets off with two trains at the same time at a speed of 30 km/h, it sets off from Beijing, meets another car, and then returns to fly in the opposite direction, so it flies back and forth between the two trains in turn until the two trains meet. How long did the bird fly? You have four jars containing pills, and each pill has a certain weight. The contaminated pill is the weight of the uncontaminated pill+1. Weighing only once, how to judge which can of medicine is contaminated? 4. The three switches outside the door correspond to the three indoor light areas respectively, and the wiring is good. When you control the switch outside the door, you can't see the light in the room. Now you are only allowed to enter the door once, and determine the corresponding relationship between the switch and the light? 5. Why does RMB only have a face value of 1, 2,5, 10? 6. You have two cans, 50 red marbles and 50 blue marbles. Choose a jar at random and put a marble in the jar at random. How do you give the best chance to choose red marbles? What are the chances of getting the red ball in your plan?
No answer type
Introduction: These questions are obviously not testing your intelligence. The test is your reaction ability. Most of these questions have no answers, but it depends on your reaction!
Detailed introduction:
1. Why is the cover of the sewer round? 2. How many cars are there in China? 3. Insert the car key into the door, which direction can you turn it to unlock the car? 4. If you want to remove any of China's 34 provinces (including autonomous regions, municipalities directly under the Central Government, Hongkong, Macao Special Administrative Region and Taiwan Province Province), which one would you remove and why? 5. How many gas stations in China can satisfy all cars? 6. Imagine that you are standing in front of a mirror. Excuse me, why can the image in the mirror be upside down, but not upside down? 7. Why is it that when hot water is turned on in any hotel, it will gush out instantly? 8. How do you explain the use of Excel to your grandmother? 9. How do you redesign and redesign an ATM? 10. If you have to learn a new computer language again, how do you plan to start? 1 1. If you plan to get a return within five years of your career, what is the motivation to get a return? Who is the audience? 12. If Microsoft told you that we would invest 5 million dollars to start your investment plan, what kind of business plan would you start? Why? 13. If you could gather computer manufacturers all over the world in one office and tell them that they would be forced to do one thing, what would it be?
draw the line
Introduction: (3 minutes -20 minutes)
Detailed introduction:
Draw 10 straight lines on 9 points, and require at least three points on each straight line?
Weigh the ball
Introduction: (5 minutes-1 hour)
Detailed introduction:
There are 12 balls and a balance. Now we know that only one ball has a different weight from the others. How can I find the ball after three times? 13? Note that this problem does not indicate whether the weight of the ball is light or heavy, so it needs careful consideration. )
ask the way
Introduction: (20 seconds -2 minutes)
Detailed introduction:
A fork in the road leads to an honest country and a lying country. Two people came, one from an honest country and the other from a lying country. An honest country always tells the truth, and a liar always tells lies. Now you are going to a country that lies, but you don't know which way to go. You need to ask these two people. How should I ask?
Weigh water
Introduction: (40 seconds -3 minutes) Answer
Detailed introduction:
If you have unlimited water, a 3-liter spatula and a 5-liter spatula, and the shapes of the two spatulas are uneven, how can you accurately weigh 4 liters of water?
Determine the color
Introduction: (5 seconds-1 min) Answer
Detailed introduction:
You have a bucket of jelly, including yellow, green and red. Close your eyes and grab two of the same color. How many can you catch to make sure you have two jellies of the same color?
Title: One Piece Divides Gems [Intelligence Test]
Content: In the United States, it is said that the average annual salary of people who can answer this question within 20 minutes is more than 80,000 dollars. This is a very interesting reasoning problem.
Detailed introduction:
In the United States, it is said that the average annual salary of people who can answer this question within 20 minutes is over 80,000 dollars. This is a very interesting reasoning problem. According to statistics, the average annual salary of people who can answer this question within 20 minutes in the United States is over 80,000 dollars. Five pirates took 100 jewels, each of which was the same size and priceless. They decided to divide it like this: 1. Draw lots to decide your own number (1, 2, 3, 4, 5) 2. First, 1 put forward the distribution plan, and then five people voted. If and only if half or more people agree, they will be distributed according to his proposal, otherwise they will be thrown into the sea to feed sharks. 3。 If 1 dies, No.2 will propose a distribution plan, and then four people will vote. If and only if half or more people agree, they will be distributed according to his proposal, otherwise they will be thrown into the sea to feed sharks. 4。 And so on ... conditions: every pirate is a very smart person who can rationally judge gains and losses and make choices. Question: What distribution scheme did the first pirate propose to maximize his income?
Calculate the coincidence number of hands
Introduction: (5 minutes-15 minutes)
Detailed introduction:
How many times do the hour hand, minute hand and second hand of a clock completely coincide in a 24-hour day? When are they? How did you work it out?
Time problem
Introduction: (I thought about this question for an hour)
Detailed introduction:
It takes 1 hour to burn an uneven rope from beginning to end. Now several ropes are made of the same material. How to time an hour and fifteen minutes by burning rope?
Bridge problem
Introduction: None
Detailed introduction:
In the dark, four travelers came to a narrow bridge without guardrails. If you don't use a flashlight, no one will dare to cross the bridge anyway. Unfortunately, four people only brought flashlights, and the bridge was so narrow that two people couldn't cross at the same time. If you cross the bridge separately, the time required for four people is 1, 2, 5 and 8 minutes respectively; And if two people cross the bridge at the same time, the time needed is the time needed for the slower person to act alone. The problem is how to design a plan to let these four people cross the bridge as soon as possible.