Super difficult puzzle, only 1 out of 100 players can find the answer

This puzzle requires players to use their keen observation and logical thinking skills. At first glance, the question seems easy to solve, similar to some math problems from school, but the pressure to come up with a solution in 20 seconds causes many people to give up.

If you pass the challenge, you are said to have an admirable IQ. Comment your answer and see how many people think the same as you.

Hieu Lam

Source: https://vtcnews.vn/cau-do-sieu-kho-100-nguoi-choi-moi-co-1-nguoi-tim-ra-dap-an-ar905436.html