Bosnia and Herzegovina JBMO TST 2016 Problem 2
Source: Bosnia and Herzegovina Junior Balkan Mathematical Olympiad TST 2016
September 16, 2018
Coloringgreatest common divisorcombinatorics
Problem Statement
We color numbers in two colors, blue and yellow, such that both colors are used (not all numbers are colored in one color). Determine number of ways we can color those numbers, such that product of all blue numbers and product of all yellow numbers have greatest common divisor .