This page is meant to be a brief introduction to a deceptively strong tool in prowing extremal and Ramsey - type thenrems in combinatories called the Pigeonhole Prineiple The applications of the Pigeonhole Principle in this worksheet are in elementary namber theory and discrete goometry.
a.Prove the pigeonhole: If there are pigeonholes and + I pigeons, then there is at least one pigeonhole with more thas one pigeon in it .
