Counting pairs — AMC & AIME Problems
Practice every real AMC 8, AMC 10, AMC 12, and AIME problem that uses counting pairs — a combinatorics concept — each with a professionally curated solution, many with a video solution too, from LIVE by Po-Shen Loh. Browse all concepts or the full past-contest archive.
All of these problems are used with official legal permission of the Mathematical Association of America (MAA).
AMC 10
2002 AMC 10B Problem 18 · 2004 AMC 10A Problem 13 · 2017 AMC 10A Problem 8 · 2021 AMC 10B Spring Problem 4 · 2021 AMC 10B Fall Problem 21 · 2024 AMC 10A Problem 6
AIME
1997 AIME Problem 10 · 1998 AIME Problem 2 · 2001 AIME I Problem 10 · 2001 AIME II Problem 10 · 2002 AIME I Problem 5 · 2003 AIME I Problem 3 · 2004 AIME II Problem 10 · 2010 AIME II Problem 3 · 2010 AIME II Problem 4 · 2013 AIME I Problem 15 · 2015 AIME II Problem 5 · 2018 AIME I Problem 9 · 2019 AIME I Problem 2