RMO Mock Math Problems 2024
RMO Mock Math Problems 2024
3. Determine whether there exists positive integers a1 < a2 < · · · < ak such that all sums
ai + aj , where 1 ≤ i < j ≤ k, are unique, and among those sums, there are 1000 consec-
utive integers.
4. Determine all positive integers n such that all positive integers less than or equal to
n and relatively prime to n are pairwise coprime.
6. 100 people from 50 countries, two from each countries, stay on a circle. Prove that
one may partition them onto 2 groups in such way that neither no two countrymen,
nor three consecutive people on a circle, are in the same group.