IMO Problems and Solutions

This page lists the authors and the proposing countries of the problems of the IMO.

To the current moment, there is only one problem that has two proposing countries: Half of problem 1994/2 (the if-part) was proposed by Australia and the other half (the only-if part) by Armenia.

1 1959
2 1960
3 1961
4 1962
5 1963
6 1964
7 1965
8 1966
9 1967
10 1968
11 1969
12 1970
13 1971
14 1972
15 1973
16 1974
17 1975
18 1976
19 1977
20 1978
21 1979
22 1980
23 1981
24 1982
25 1983
26 1984
27 1985
28 1986
29 1987
30 1988
31 1989
32 1990
33 1991
34 1992
35 1993
36 1994
37 1995
38 1996
39 1997
40 1998
41 1999
42 2000
43 2001
44 2002
45 2003
46 2004
47 2005
48 2006
49 2007
50 2008
51 2009
52 Comment
53 See also

1959

1959 IMO (in Romania)
1959 IMO Problems
Problem 1 proposed by Poland
Problem 2 proposed by Constantin Ionescu-Tiu, Romania
Problem 3 proposed by Hungary
Problem 4 proposed by Hungary
Problem 5 proposed by Cezar Cosnita, Romania
Problem 6 proposed by Czechoslovakia

1960

1960 IMO (in Romania)
1960 IMO Problems
Problem 1 proposed by Bulgaria
Problem 2 proposed by Hungary
Problem 3 proposed by Gheorghe D. Simionescu, Romania
Problem 4 proposed by Hungary
Problem 5 proposed by Czechoslovakia
Problem 6 proposed by Bulgaria
Problem 7 proposed by East Germany

1961

1961 IMO (in Hungary)
1961 IMO Problems
Problem 1 proposed by Hungary
Problem 2 proposed by Poland
Problem 3 proposed by Bulgaria
Problem 4 proposed by East Germany
Problem 5 proposed by Czechoslovakia
Problem 6 proposed by Gheorghe D. Simionescu, Romania

1962

1962 IMO (in Czechoslovakia)
1962 IMO Problems
Problem 1 proposed by Poland
Problem 2 proposed by Hungary
Problem 3 proposed by Czechoslovakia
Problem 4 proposed by Cezar Cosnita, Romania
Problem 5 proposed by Bulgaria
Problem 6 proposed by East Germany
Problem 7 proposed by USSR

1963

1963 IMO (in Poland)
1963 IMO Problems
Problem 1 proposed by Czechoslovakia
Problem 2 proposed by USSR
Problem 3 proposed by Hungary
Problem 4 proposed by USSR
Problem 5 proposed by Wolfgang Engel, East Germany
Problem 6 proposed by Hungary

1964

1964 IMO (in USSR)
1964 IMO Problems
Problem 1 proposed by Czechoslovakia
Problem 2 proposed by Hungary
Problem 3 proposed by Yugoslavia
Problem 4 proposed by Hungary
Problem 5 proposed by Gheorghe D. Simionescu, Romania
Problem 6 proposed by Poland

1965

1965 IMO (in East Germany)
1965 IMO Problems
Problem 1 proposed by Yugoslavia
Problem 2 proposed by Poland
Problem 3 proposed by Czechoslovakia
Problem 4 proposed by USSR
Problem 5 proposed by Gheorghe D. Simionescu, Romania
Problem 6 proposed by Poland

1966

1966 IMO (in Bulgaria)
1966 IMO Problems
Problem 1 proposed by USSR
Problem 2 proposed by Hungary
Problem 3 proposed by Bulgaria
Problem 4 proposed by Yugoslavia
Problem 5 proposed by Czechoslovakia
Problem 6 proposed by Poland

1967

1967 IMO (in Yugoslavia)
1967 IMO Problems
Problem 1 proposed by Poland
Problem 2 proposed by Czechoslovakia
Problem 3 proposed by United Kingdom
Problem 4 proposed by Tullio Viola, Italy
Problem 5 proposed by USSR
Problem 6 proposed by Hungary

1968

1968 IMO (in USSR)
1968 IMO Problems
Problem 1 proposed by Unknown Author, Romania (taken from a Romanian problem book)
Problem 2 proposed by Czechoslovakia
Problem 3 proposed by Bulgaria
Problem 4 proposed by Poland
Problem 5 proposed by East Germany
Problem 6 proposed by David Monk, United Kingdom

1969

1969 IMO (in Romania)
1969 IMO Problems
Problem 1 proposed by Wolfgang Engel, East Germany
Problem 2 proposed by Hungary
Problem 3 proposed by Poland
Problem 4 proposed by Netherlands
Problem 5 proposed by A. Mekei, Mongolia
Problem 6 proposed by USSR

1970

1970 IMO (in Hungary)
1970 IMO Problems
Problem 1 proposed by Poland
Problem 2 proposed by Dumitru Batinetzu, Romania
Problem 3 proposed by Åke Samuelsson, Sweden
Problem 4 proposed by Czechoslovakia
Problem 5 proposed by Bulgaria
Problem 6 proposed by USSR

1971

1971 IMO (in Czechoslovakia)
1971 IMO Problems
Problem 1 proposed by Hungary
Problem 2 proposed by USSR
Problem 3 proposed by Poland
Problem 4 proposed by Netherlands
Problem 5 proposed by Bulgaria
Problem 6 proposed by Sweden

1972

1972 IMO (in Poland)
1972 IMO Problems
Problem 1 proposed by USSR
Problem 2 proposed by Netherlands
Problem 3 proposed by United Kingdom
Problem 4 proposed by Netherlands
Problem 5 proposed by Bulgaria
Problem 6 proposed by United Kingdom

1973

1973 IMO (in USSR)
1973 IMO Problems
Problem 1 proposed by Czechoslovakia
Problem 2 proposed by Poland
Problem 3 proposed by Åke Samuelsson, Sweden
Problem 4 proposed by Yugoslavia
Problem 5 proposed by Poland
Problem 6 proposed by Åke Samuelsson, Sweden

1974

1974 IMO (in East Germany)
1974 IMO Problems
Problem 1 proposed by Murray Klamkin, USA
Problem 2 proposed by Matti Lehtinen, Finland
Problem 3 proposed by Ciprian Borcea, Romania
Problem 4 proposed by Bulgaria
Problem 5 proposed by Jan van de Craats, Netherlands
Problem 6 proposed by Sweden

1975

1975 IMO (in Bulgaria)
1975 IMO Problems
Problem 1 proposed by Czechoslovakia
Problem 2 proposed by United Kingdom
Problem 3 proposed by Jan van de Craats, Netherlands
Problem 4 proposed by USSR
Problem 5 proposed by USSR
Problem 6 proposed by David Monk, United Kingdom

1976

1976 IMO (in Austria)
1976 IMO Problems
Problem 1 proposed by Czechoslovakia
Problem 2 proposed by Matti Lehtinen, Finland
Problem 3 proposed by Jan van de Craats, Netherlands
Problem 4 proposed by Murray Klamkin, USA
Problem 5 proposed by Jan van de Craats, Netherlands
Problem 6 proposed by Robert Lyness and David Monk, United Kingdom

1977

1977 IMO (in Yugoslavia)
1977 IMO Problems
Problem 1 proposed by Jan van de Craats, Netherlands
Problem 2 proposed by Phan Duc Chinh, Vietnam
Problem 3 proposed by Jan van de Craats, Netherlands
Problem 4 proposed by David Monk, United Kingdom
Problem 5 proposed by Hermann Frasch, West Germany
Problem 6 proposed by Ivan Prodanov, Bulgaria

1978

1978 IMO (in Romania)
1978 IMO Problems
Problem 1 proposed by Cuba
Problem 2 proposed by Murray Klamkin, USA
Problem 3 proposed by United Kingdom
Problem 4 proposed by Murray Klamkin, USA
Problem 5 proposed by France
Problem 6 proposed by Jan van de Craats, Netherlands

1979

1979 IMO (in United Kingdom)
1979 IMO Problems
Problem 1 proposed by Arthur Engel, West Germany
Problem 2 proposed by Nickolay Khadzhiivanov and Nedjalko Nenov, Bulgaria
Problem 3 proposed by Nikolai Vasil'ev and Igor F. Sharygin, USSR
Problem 4 proposed by Murray Klamkin, USA
Problem 5 proposed by Joe Gillis, Israel
Problem 6 proposed by Arthur Engel, West Germany

1980

There was no IMO in 1980

1981

1981 IMO (in USA)
1981 IMO Problems
Problem 1 proposed by David Monk, United Kingdom
Problem 2 proposed by Arthur Engel, West Germany
Problem 3 proposed by Jan van de Craats, Netherlands
Problem 4 proposed by Belgium
Problem 5 proposed by USSR
Problem 6 proposed by Juha Oikkonen, Finland

1982

1982 IMO (in Hungary)
1982 IMO Problems
Problem 1 proposed by David Monk, United Kingdom
Problem 2 proposed by Jan van de Craats, Netherlands
Problem 3 proposed by Alexander N. Grishkov, USSR
Problem 4 proposed by David Monk, United Kingdom
Problem 5 proposed by Jan van de Craats, Netherlands
Problem 6 proposed by Van Nhu Cuong, Vietnam

1983

1983 IMO (in France)
1983 IMO Problems
Problem 1 proposed by David Monk, United Kingdom
Problem 2 proposed by Igor F. Sharygin, USSR
Problem 3 proposed by Arthur Engel, West Germany
Problem 4 proposed by Belgium
Problem 5 proposed by Marcin Kuczma, Poland
Problem 6 proposed by Murray Klamkin, USA

1984

1984 IMO (in Czechoslovakia)
1984 IMO Problems
Problem 1 proposed by Michael Stoll and Bruno Haible, West Germany
Problem 2 proposed by Aiko Tiggelaar, Netherlands
Problem 3 proposed by Ioan Tomescu, Romania
Problem 4 proposed by Laurentiu Panaitopol, Romania
Problem 5 proposed by Tserendorj Dashdorj, Mongolia
Problem 6 proposed by Poland

1985

1985 IMO (in Finland)
1985 IMO Problems
Problem 1 proposed by Frank Budden, United Kingdom
Problem 2 proposed by George Szekeres, Australia
Problem 3 proposed by Jan van de Craats, Netherlands
Problem 4 proposed by R. Gonchigdorj, Mongolia
Problem 5 proposed by Igor F. Sharygin, USSR
Problem 6 proposed by Åke Samuelsson, Sweden

1986

1986 IMO (in Poland)
1986 IMO Problems
Problem 1 proposed by Arthur Engel, West Germany
Problem 2 proposed by Gengzhe Chang and Dongxu Qi, China
Problem 3 proposed by Elias Wegert, East Germany
Problem 4 proposed by Sven Sigurðsson, Iceland
Problem 5 proposed by David Monk, United Kingdom
Problem 6 proposed by Konrad Engel, East Germany

1987

1987 IMO (in Cuba)
1987 IMO Problems
Problem 1 proposed by Horst Sewerin, West Germany
Problem 2 proposed by I.A. Kushnir, USSR
Problem 3 proposed by Arthur Engel, West Germany
Problem 4 proposed by Nguyen Minh Duc, Vietnam
Problem 5 proposed by Hans-Dietrich Gronau, East Germany
Problem 6 proposed by Vsevolod F. Lev, USSR

1988

1988 IMO (in Australia)
1988 IMO Problems
Problem 1 proposed by Lucien Kieffer, Luxembourg
Problem 2 proposed by Czechoslovakia
Problem 3 proposed by David Monk, United Kingdom
Problem 4 proposed by Finbarr Holland, Ireland
Problem 5 proposed by Dimitris Kontogiannis, Greece
Problem 6 proposed by Stephan Beck, West Germany

1989

1989 IMO (in West Germany)
1989 IMO Problems
Problem 1 proposed by Jose Marasigan, Philippines
Problem 2 proposed by Esther Szekeres, Australia
Problem 3 proposed by Harm Derksen, Netherlands
Problem 4 proposed by Eggert Briem, Iceland
Problem 5 proposed by Bernt Lindström, Sweden
Problem 6 proposed by Marcin Kuczma, Poland

1990

1990 IMO (in China)
1990 IMO Problems
Problem 1 proposed by C.R. Pranesachar, India
Problem 2 proposed by Pavol Černek, Czechoslovakia
Problem 3 proposed by Laurentiu Panaitopol, Romania
Problem 4 proposed by Albert Erkip, Turkey
Problem 5 proposed by Hagen von Eitzen, West Germany
Problem 6 proposed by Harm Derksen, Netherlands

1991

1991 IMO (in Sweden)
1991 IMO Problems
Problem 1 proposed by Arkadii Skopenkov, USSR
Problem 2 proposed by Laurentiu Panaitopol, Romania
Problem 3 proposed by Chengzhang Li, China
Problem 4 proposed by Cecil Rousseau, USA
Problem 5 proposed by Johan Yebbou, France
Problem 6 proposed by Harm Derksen, Netherlands

1992

1992 IMO (in Russia)
1992 IMO Problems
Problem 1 proposed by Achim Zulauf, New Zealand
Problem 2 proposed by Belur Jana Venkatachala, India
Problem 3 proposed by Chengzhang Li, China
Problem 4 proposed by Johan Yebbou, France
Problem 5 proposed by Stefano Mortola, Italy
Problem 6 proposed by Tony Gardiner, United Kingdom

1993

1993 IMO (in Turkey)
1993 IMO Problems
Problem 1 proposed by Tom Laffey, Ireland
Problem 2 proposed by David Monk, United Kingdom
Problem 3 proposed by Kerkko Luosto, Finland
Problem 4 proposed by Donco Dimovski, Macedonia
Problem 5 proposed by Elias Wegert, Germany
Problem 6 proposed by Nicholas de Bruijn, Netherlands

1994

1994 IMO (in Hong Kong)
1994 IMO Problems
Problem 1 proposed by Vincent Lafforgue, France
Problem 2 proposed by Hans Lausch, Australia and Garnik Tonoyan, Armenia (independently)
Problem 3 proposed by Gabriel Istrate, Romania
Problem 4 proposed by Hans Lausch, Australia
Problem 5 proposed by David Monk, United Kingdom
Problem 6 proposed by Kerkko Luosto, Finland

1995

1995 IMO (in Canada)
1995 IMO Problems
Problem 1 proposed by Borislav Mihailov, Bulgaria
Problem 2 proposed by Nazar Agakhanov, Russia
Problem 3 proposed by Jaromír Šimša, Czech Republic
Problem 4 proposed by Marcin Kuczma, Poland
Problem 5 proposed by Alastair McNaughton, New Zealand
Problem 6 proposed by Marcin Kuczma, Poland

1996

1996 IMO (in India)
1996 IMO Problems
Problem 1 proposed by Kerkko Luosto, Finland
Problem 2 proposed by Jeffrey Grossman, Canada
Problem 3 proposed by Mircea Becheanu, Romania
Problem 4 proposed by Alexander S. Golovanov, Russia
Problem 5 proposed by Nairi Sedrakyan, Armenia
Problem 6 proposed by Laurent Rosaz, France

1997

1997 IMO (in Argentina)
1997 IMO Problems
Problem 1 proposed by Igor Akylich and Igor Voronovich, Belarus
Problem 2 proposed by David Monk, United Kingdom
Problem 3 proposed by Oleg Bogopolsky, Russia
Problem 4 proposed by Ebadollah S. Mahmoodian and Mohammad Mahdian, Iran
Problem 5 proposed by Petr Kanovsky, Czech Republic
Problem 6 proposed by Giedrius Alkauskas, Lithuania

1998

1998 IMO (in Taiwan)
1998 IMO Problems
Problem 1 proposed by Charles Leytem, Luxembourg
Problem 2 proposed by R.B. Bapat, India
Problem 3 proposed by Igor Voronovich, Belarus
Problem 4 proposed by David Monk, United Kingdom
Problem 5 proposed by Vyacheslav Yasinsky, Ukraine
Problem 6 proposed by Oleg Mushkarov and Nikolai Nikolov, Bulgaria

1999

1999 IMO (in Romania)
1999 IMO Problems
Problem 1 proposed by Jan Willemson, Estonia
Problem 2 proposed by Marcin Kuczma, Poland
Problem 3 proposed by Eugenii Barabanov and Igor Voronovich, Belarus
Problem 4 proposed by Liang-Ju Chu, Taiwan
Problem 5 proposed by Pavel Kozhevnikov, Russia
Problem 6 proposed by Tetsuya Ando, Japan

2000

2000 IMO (in South-Korea)
2000 IMO Problems
Problem 1 proposed by Sergei Berlov, Russia
Problem 2 proposed by Titu Andreescu, USA
Problem 3 proposed by Sergei Shikh and Igor Voronovich, Belarus
Problem 4 proposed by Sándor Dobos, Hungary
Problem 5 proposed by Valerii Senderov, Russia
Problem 6 proposed by Lev and Tatiana Emelianovii, Russia

2001

2001 IMO (in USA)
2001 IMO Problems
Problem 1 proposed by Hojoo Lee, South Korea
Problem 2 proposed by Hojoo Lee, South Korea
Problem 3 proposed by Christian Bey, Germany
Problem 4 proposed by Bill Sands, Canada
Problem 5 proposed by Shay Gueron, Israel. (Also: Problem 2501 in Crux Mathematicorum, February 2000)
Problem 6 proposed by Aleksander Ivanov, Bulgaria

2002

2002 IMO (in United Kingdom)
2002 IMO Problems
Problem 1 proposed by Federico Ardila, Colombia
Problem 2 proposed by Hojoo Lee, South Korea
Problem 3 proposed by Laurentiu Panaitopol, Romania
Problem 4 proposed by Mihai Manea, Romania
Problem 5 proposed by Belur Jana Venkatachala, India
Problem 6 proposed by Vyacheslav Yasinsky, Ukraine

2003

2003 IMO (in Japan)
2003 IMO Problems
Problem 1 proposed by Carlos Gustavo Moreira, Brazil
Problem 2 proposed by Aleksander Ivanov, Bulgaria
Problem 3 proposed by Waldemar Pompe, Poland
Problem 4 proposed by Matti Lehtinen, Finland
Problem 5 proposed by Finbarr Holland, Ireland
Problem 6 proposed by Johan Yebbou, France

2004

2004 IMO (in Greece)
2004 IMO Problems
Problem 1 proposed by Dinu Serbanescu and Valentin Vornicu, Romania
Problem 2 proposed by Hojoo Lee, South Korea
Problem 3 proposed by Jan Willemson, Estonia
Problem 4 proposed by Hojoo Lee, South Korea
Problem 5 proposed by Waldemar Pompe, Poland
Problem 6 proposed by Mohsen Jamaali and Armin Morabbi, Iran

2005

2005 IMO (in Mexico)
2005 IMO Problems
Problem 1 proposed by Bogdan Enescu, Romania
Problem 2 proposed by Nicholas de Bruijn, Netherlands
Problem 3 proposed by Hojoo Lee, South Korea
Problem 4 proposed by Mariusz Skalba, Poland
Problem 5 proposed by Waldemar Pompe, Poland
Problem 6 proposed by Radu Gologan and Dan Schwarz, Romania

2006

2006 IMO (in Slovenia)
2006 IMO Problems
Problem 1 proposed by Hojoo Lee, South Korea
Problem 2 proposed by Dušan Djukić, Serbia
Problem 3 proposed by Finbarr Holland, Ireland
Problem 4 proposed by Zuming Feng, USA
Problem 5 proposed by Dan Schwarz, Romania
Problem 6 proposed by Dušan Djukić, Serbia

2007

2007 IMO (in Vietnam)
2007 IMO Problems
Problem 1 proposed by Michael Albert, New Zealand
Problem 2 proposed by Charles Leytem, Luxembourg
Problem 3 proposed by Vasily Astakhov, Russia
Problem 4 proposed by Marek Pechal, Czech Republic
Problem 5 proposed by Kevin Buzzard and Edward Crane, United Kingdom
Problem 6 proposed by Gerhard Woeginger, Netherlands

2008

2008 IMO (in Spain)
2008 IMO Problems
Problem 1 proposed by Andrey Gavrilyuk, Russia
Problem 2 proposed by Walther Janous, Austria
Problem 3 proposed by Kęstutis Česnavičius, Lithuania
Problem 4 proposed by Hojoo Lee, South Korea
Problem 5 proposed by Bruno Le Floch and Ilia Smilga, France
Problem 6 proposed by Vladimir Shmarov, Russia

2009

2009 IMO (in Germany)
2009 IMO Problems
Problem 1 proposed by Ross Atkins, Australia
Problem 2 proposed by Sergei Berlov, Russia
Problem 3 proposed by Gabriel Carroll, USA
Problem 4 proposed by Hojoo Lee, Peter Vandendriessche, and Jan Vonk, Belgium
Problem 5 proposed by Bruno Le Floch, France
Problem 6 proposed by Dmitry Khramtsov, Russia

Comment