Maths Olympiad Prep

Library / /5 of 348

Combinatorics Difficulty 4.3 AIME Find the answer

Compute the smallest positive integer that does not appear in any problem statement on any round at HMMT November 2023.

A number or a short expression. Spacing and $ signs are ignored.

Solution

The number 22 does not appear on any round. On the other hand, the numbers 1 through 21 appear as follows. NumberRoundProblem1Guts212Guts133Guts174Guts135Guts146Guts27Guts108Guts139Guts2810Guts1011General312Guts3213Theme814Guts1915Guts1716Guts3017Guts2018Guts219Guts3320Guts321Team7\begin{array}{c|c|c} Number & Round & Problem \\ \hline 1 & Guts & 21 \\ 2 & Guts & 13 \\ 3 & Guts & 17 \\ 4 & Guts & 13 \\ 5 & Guts & 14 \\ 6 & Guts & 2 \\ 7 & Guts & 10 \\ 8 & Guts & 13 \\ 9 & Guts & 28 \\ 10 & Guts & 10 \\ 11 & General & 3 \\ 12 & Guts & 32 \\ 13 & Theme & 8 \\ 14 & Guts & 19 \\ 15 & Guts & 17 \\ 16 & Guts & 30 \\ 17 & Guts & 20 \\ 18 & Guts & 2 \\ 19 & Guts & 33 \\ 20 & Guts & 3 \\ 21 & Team & 7 \end{array}

Want a route through all this instead of an archive? The track puts 2,000 problems in a working order, from AMC 10 level to the IMO shortlist.

Source: Omni-MATH, licensed Apache-2.0. Statement and solution reproduced as published; topic and difficulty added by this site.