TOT 038 1983 Spring J-A5 4 in 5, are divisible by others or not, of 17
Source:
August 18, 2019
number theorydivisibleDividecombinatorics
Problem Statement
Prove that in any set of distinct natural numbers one can either find five numbers so that four of them are divisible into the other or five numbers none of which is divisible into any other.(An established theorem)