This Simple Math Problem Was Solved By 90% Of People 30 Years Ago. Now, 1 In 2 People Don't Know The Answer!
The clip went viral on the internet with almost 1 million views and 1,350 comments.
A seemingly trivial math problem created discussions in Japan.
According to the YouTube channel, MindYourDecision, one study found that only 60% of people over 20 years manages to find the right answer.
The video clearly explains the mistake that people make.
What answer did you find? - 9 or 1? See the clip which is the correct version!