MathCastle
Counting & ProbabilitySuperchallengeCounting Strategies: Casework, Complementary & Overcounting

Counting Strategies: Casework, Complementary & Overcounting · Superchallenge problem

A 1×121\times12 strip is to be tiled using 1×11\times1 red tiles and 1×21\times2 blue domino tiles (tiles placed end to end, filling the strip exactly). How many tilings use at most 33 blue dominoes?