MathDB
Considering the number of words with parity

Source: Middle European Mathematical Olympiad 2012 - Team Compt. T-3

September 14, 2012
combinatorics proposedcombinatorics

Problem Statement

Let n n be a positive integer. Consider words of length nn composed of letters from the set {M,E,O} \{ M, E, O \} . Let a a be the number of such words containing an even number (possibly 0) of blocks ME ME and an even number (possibly 0) blocks of MO MO . Similarly let b b the number of such words containing an odd number of blocks ME ME and an odd number of blocks MO MO . Prove that a>b a>b .
Back to ProblemsView on AoPS