Видео с ютуба Maths Problem With Solution

The Simplest Math Problem No One Can Solve - Collatz Conjecture

Germany | Can you solve? | A Nice Math olympiad question Solution |

The hardest problem on the hardest test

Математическая задача: Решение задачи «Соедини города» (Задача о автомагистрали)

Math problem for advanced students

Killer Math Problem With An Unbelievably Elegant Solution