Question

Find with proof the minimum possible k such that every subset of f1; 2; : : : ; 2022g of size k must contain at least two elements a; b such that a < b and b is a multiple of a.

Answer 1

Minimum possible K = 307

Explanation:

Attached below is the detailed solution

Given set { 1, 2 , .......... 2022 }

The largest subset will contain prime numbers because they are not multiples of any number but 1