Combinatorial Identities

This handout covers all of the material you need to know to solve most AMC and AIME problems that use combinatorial identities. It covers Pascal’s Identity, the Hockey-Stick identity, Vandermonde’s Identity, and more, giving complete proofs of each of these ideas.

These proofs and descriptions are also followed up by worked example problems as well as exercises left to the reader.

This handout assumes knowledge of basic counting techniques, such as permuting objects, etc.

Last Updated: March 4, 2021