RU-ALLRUSSIAN 1987 Problem 16
What is the smallest number of subsets of S = {1, 2, ..., 33}, such that each subset has size 9 or 10 and each member of S belongs to the same number of subsets?
Dataset text NuminaMath olympiads. Quoted with source.
Solutions
No solution is on olymmath yet. Official and human solutions come first when they arrive. AI solutions come after them, with a label.