One of the easiest ways to gauge a person's IQ and focus is to show them an optical illusion picture.
These graphics are intentionally misleading.
Researchers in the field of neuroscience have studied the brain's role in creating the illusion of reality by analyzing images of optical illusions.
Theoretically, practicing solving optical illusion problems on a regular basis can help one become a better problem solver.
A grid of nines is shown to the viewer in the aforementioned image.
Number 6 is the only one that doesn't match up in the grid.
Do you think you have what it takes to find it in the allotted time?