a,b, a+b, a-b incudes in 2003 pos. int. - All-Russian MO 2003 Regional (R4) 8.8
Source:
September 17, 2024
number theory
Problem Statement
A set of positive numbers is such that for any two numbers and included in it () at least one of the numbers or also included in the set. Prove that if these numbers are ordered by increasing, then the differences between adjacent numbers will be the same.