OlympiadProblems.pdf

PolyaHowToSolveIt.pdf

Past Putnam exams

1980
1990
2000
1981
1991
2001
1982
1992
2002
1983
1993
2003
1984
1994
2004
1985
1995
2005
1986
1996
1987
1997
1988
1998
1989
1999