The International Olympic Mathematics Competition is hosted by the participating countries in turn, and the funds are provided by the host countries, but the travel expenses are borne by the participating countries themselves. Each group has at most 6 middle school students, a team leader, a deputy team leader and observers. Participants must be under the age of 20 at the time of competition and cannot have any higher education above secondary school; There is no limit to the number of times you can participate in IMO.

Because the team leader knows the problem, he can't get in touch with the contestants until after the game. They stayed at the hotel arranged by the conference, and the location was not announced. Team members are led by the deputy team leader and sometimes accompanied by observers. They live in university dormitories and are not allowed to communicate with the outside world, including making phone calls and surfing the Internet. The conference also arranged a tour guide for each participating team to take care of the team members, explain the schedule and rules to the team members, lead the team members to and from various places, and arrange sightseeing activities after the game. The accommodation and food expenses of the team leader, deputy team leader and contestants shall be borne by the conference, and the expenses of observers shall be borne by themselves. Since the 24th session (1983), IMO papers have been composed of 6 questions, with 7 points for each question, out of 42 points. The competition is divided into two days, and participants have 4.5 hours to solve three problems every day (9 am to 65438+ 0: 30 pm). Usually 1 questions (i.e. 1 and 4 questions) are the simplest, 2 questions (i.e., 2 and 5 questions) are moderate, and 3 questions (i.e., 3 and 6 questions) are the most difficult. All the topics are not beyond the recognized scope of middle school mathematics curriculum, and are generally divided into four categories: algebra, geometry, number theory and combinatorial mathematics.

IMO topic is rooted in middle school mathematics, but it is developed on specific knowledge and requires higher methods. Generally speaking, IMO topics are difficult and flexible. To solve these problems, participants generally do not need to have advanced mathematical knowledge (such as calculus), but need to have the correct way of thinking, good mathematical literacy and basic skills, perseverance and creativity. In principle, IMO does not encourage players to use mathematical knowledge and tools outside the scope of middle school to solve problems (but there are no clear restrictions), and this will be fully considered when determining the topic. Considering the above characteristics, IMO test questions and their multiple-choice questions, together with some mathematical competition and training questions from various countries, represent a special kind of mathematics between elementary mathematics and advanced mathematics-competition mathematics.

The drafting method of the competition provides questions and answers for participating countries except the host country, and the host country forms a drafting Committee to select candidate topics from the submitted topics. Team leaders from various countries arrived a few days earlier than the team members, and discussed the questions and official answers. Each team leader translated the test questions into his own language. Candidates who are not selected will be announced before the next competition so that participating countries can use them for training and testing. Generate 6 test questions. The host country does not provide test questions. After the test questions are determined, they will be written in English, French, German, Russian and other working languages, and the team leader will translate them into the national language. The examiners' committee is composed of leaders of various countries and the chairman designated by the host country. This chairman is usually the authority on mathematics in this country.

There are seven duties of the examiners' committee: 1), selecting examination questions; 2), determine the scoring standard; 3) Accurately express the test questions in the working language, and translate and approve the test questions translated into the languages of the participating countries; 4) During the competition, determine how to answer students' questions in writing; 5) Resolve the different opinions on grading between individual team leaders and coordinators; 6) Determine the number and scores of medals.

IMO test questions of the 48th International Mathematical Olympiad in 2007 were provided by the following countries.

Question 1: New Zealand;

Question 2: Luxembourg;

Question 3: Russia;

Question 5: Britain;

Question 6: Netherlands;

IMO test questions of the 49th International Mathematical Olympiad in 2008 were provided by the following countries.

Andrey Gavrilyuk of Russia provided the question 1.

Question 2 is provided by Walther Janous of Austria.

Question 3: By the King of Lithuania? Stutis? Esna d? Provided by ius.

Question 4 is provided by Hojoo Lee of Korea. He has provided many questions for IMO, and people who often attend mathoe know this person.

Question 5 is provided by Bruno Le Floch and Ilia Smilga of France.

Question 6 is provided by Russian Vladimir Shmarov.

Issues provided by China to the International Maritime Organization

1986 the 27th IMO question 2, which is the first question provided by China to IMO.

Given the points P0 and △ A 1A3a3 on the plane, and it is agreed that when S≥4, As=A s-3, the point sequence P0, P 1, P2, ... is constructed so that the point P k+ 1 rotates clockwise around the center A k+ 1. It is proved that if P 1986=P0, then △A 1A2A3 is an equilateral triangle.

Chang Gengzhe of China University of Science and Technology and Qi Xu Dong of Jilin University have the same name.

199 1 the third question of the 32nd IMO, which is the second question provided by China to IMO.

Let S={ 1, 2, 3, ..., 280} and find the smallest natural number n, so that each n-ary subset of S contains five pairwise prime numbers.

Li Chengzhang of Nankai University.

1992 the third question of the 33rd IMO, which is the third question provided by China to IMO.

There are nine points in a given space, none of which is a * * * surface, and there is a line segment between each pair of points, which can be dyed red or blue or not. Find the minimum value of n, so that when each of any n line segments is dyed in any one of red and blue colors, the set of these n line segments must contain a triangle with the same color on each side.

Li Chengzhang of Nankai University.

The 40th IMO question 1999 was provided by Taiwan Province province.

Ensure that all positive integer pairs (n, p) satisfy that p is a prime number, n≤2p, and (p- 1)n+ 1 is divisible by n. Now IMO has 6 questions in each test paper, with 7 points for each question, out of 42 points.

The exam is divided into two days, 4.5 hours a day, and three questions are tested. The competition is divided into two days, and participants have 4.5 hours to solve three problems every day (9 am to 65438+ 0: 30 pm).

Usually 1 questions (that is, 1 and 4 questions) are the shallowest, 2 questions (that is, 2 and 5 questions) are medium, and 3 questions (that is, 3 and 6 questions) are the deepest. All questions are selected from different categories in the middle school mathematics curriculum, usually combinatorial mathematics, number theory, geometry and algebra, inequality. To solve these problems, contestants usually don't need more in-depth mathematical knowledge (although most contestants have it, in fact, they also need a lot of mathematical knowledge and skills outside the course), but they usually need whimsical thinking and good mathematical ability to find solutions. Previous IMO host countries, total number of champions and number of participating countries (regions)

Number of countries participating in the total score champion of the host country in that year

Romania 7

1960 Romania and the former Czechoslovakia 5

196 1 3 Hungary

Former Czechoslovakia Hungary

1963 5 Poland, former Soviet Union, 8

1964 6 The former Soviet Union 9

1965 7 the former east Germany and the former Soviet union 8

Bulgaria, former Soviet Union 9

1967 9 the former yugoslavia and the former Soviet union

1968 10 The former Soviet Union and East Germany 12

1969 1 1 Romania and Hungary

Hungary 1970 12

197 1 13 former Czechoslovakia Hungary 15

1972 14 Poland and the former Soviet union

1973 15 former Soviet union 16

1974 16 the former east Germany and the former Soviet union 18

Bulgaria Hungary 17

1976 18 Australia's former Soviet Union 19

1977 19 yugoslavia USA 2 1

1978 20 Romania 17

1979 2 1 the United States and the former Soviet union 23

198 1 22 USA 27

Hungary's former West Germany 30

1983 24 France's former West Germany 3 2

1984 the former Czechoslovakia and the former Soviet union 34

Finland Romania 42

Poland, the United States and the former Soviet Union

Cuba Romania 42

1988 Australia and the former Soviet Union 49

1989 30 former west Germany and the former Soviet union 50

1990 3 1 China

199 1 32 Sweden and the former Soviet union 56

Russian China 62

Turkish China 65

1994 35 China, Hongkong and USA

1995 36 China 73

India Romania 75

Argentine China 82

China, Taipei, Iran 84

1999 40 Romanian China, Russian 8 1

April 20001China, Korea 82

200 1 42 China USA 83

In 2002, China was 43 and Britain was 84.

2003 44 Japan Bulgaria 82

Greek China 85

2005 46 China, Mexico 98

2006 47 Slovenian China 104

2007 48 Vietnam Russia 93

2008 49 China 103.

May 2009 China 104.

China, Kazakstan 96

20 1 1 52 China 10 1.

20 12 53 Argentina and Korea 103

Colombian China 208

20 14 55 China 20 1

20 15 56 Thailand and USA

20 16 57 hongkong, China

20 17 58 Brazil has trained many excellent athletes in all previous international Olympic competitions. At present, the best player in the world is Romanian player cyprien Mano Lescu. For three years in a row, he got full marks in the international Olympic Games, including 1995, 1996 and 1997, which were the only three in the world, including 65438+.

In addition, Russia, Romania, Hungary and other Eastern European countries also have many talented teenagers who got full marks twice.

In China, Luo Wei, who got full marks of 199 1 and 1992 twice, is now a postdoctoral fellow working in Zhejiang University. Fu, who got full marks in 2002 and 2003, and Wei Dongyi, who got full marks in 2008 and 2009.