“Can you find the missing number in 15 seconds?” the brain teaser reads. This puzzle tests both your sharp vision and quick thinking under pressure. X users actively tired to solve this brain ...

Thankfully, the puzzles appear to remain the same ... There are only two possible digits that could fit here. Feel free to ...

Roula Khalaf, Editor of the FT, selects her favourite stories in this weekly newsletter.

Plus, you can let us know what you think of the puzzles by emailing at [email protected]. We look forward to hearing from you.