A collection of problems from the William Lowell Putnam Competition which places them in the context of important mathematical themes.

Kiran Kedlaya received his PhD from the Massachusetts Institute of Technology in 2000. After teaching at various other institutions, including the University of California, Berkeley, he returned to MIT as Associate Professor in 2003. He won the Presidential Early Career Award for Scientists and Engineers in 2006. He was a collaborating editor for American Mathematical Monthly and is currently a corresponding editor for International Mathematics Research Notices.

1. Problems; 2. Hints; 3. Solutions.