The 2011 putnam competition will occur this weekend.
It has been going since 1938.
For 1938-2000, the ebooks are available on the net to download for:
The William Lowell Putnam Mathematical Competition. Problems and solutions: 1938-1964, by Gleason, Greenwood and Kelly;
The William Lowell Putnam mathematical competition. Problems and solutions: 1965-1984, edited by Alexanderson, Klosinski and Larson;
The William Lowell Putnam Mathematical Competition 1985-2000: Problems, Solutions and Commentary, by Kedlaya, Poonen and Vakil.
The others from 2001-2010 are at http://amc.maa.org/a-activities/a7-problems/putnamindex.shtml
Soon the 2011 one will be there too.
It has been going since 1938.
For 1938-2000, the ebooks are available on the net to download for:
The William Lowell Putnam Mathematical Competition. Problems and solutions: 1938-1964, by Gleason, Greenwood and Kelly;
The William Lowell Putnam mathematical competition. Problems and solutions: 1965-1984, edited by Alexanderson, Klosinski and Larson;
The William Lowell Putnam Mathematical Competition 1985-2000: Problems, Solutions and Commentary, by Kedlaya, Poonen and Vakil.
The others from 2001-2010 are at http://amc.maa.org/a-activities/a7-problems/putnamindex.shtml
Soon the 2011 one will be there too.