Counting integers in a range — AMC & AIME Problems

Practice every real AMC 8, AMC 10, AMC 12, and AIME problem that uses counting integers in a range — 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 8

1986 AMC 8 Problem 7 · 2000 AMC 8 Problem 3 · 2003 AMC 8 Problem 19 · 2005 AMC 8 Problem 18 · 2008 AMC 8 Problem 22 · 2018 AMC 8 Problem 21 · 2018 AMC 8 Problem 25 · 2022 AMC 8 Problem 13

More combinatorics concepts

arrangements with restrictionsbasic countingbijectionBurnside’s LemmaCatalan Numbercircular arrangementscombinationscombinatorial gamecomplementary countingcounting intersectionscounting pairscounting regionscounting shapes in figuresderangementsdouble countingfencepost countinggenerating functionsgraph theoryinclusion-exclusionlattice pathsmultiplication principlemultiset permutationspartitions and compositionsPascal’s Trianglepermutationspigeonhole principlerecursive countingstars and barssubsetstilingtree diagramVandermonde’s ConvolutionVenn Diagram