It's quite a tall order trying to crack this tricky brainteaser in less than 10 seconds - but there is a little known hack ...

Shared by the Preston Education on X, this puzzle may appear easy at first but while surely make you think hard. The brain teaser shows four blocks with four squares inside each of them.

and the empty square. Then move tiles around in that loop. Sometimes you will have to move two blocks side-by-side in the loop. Each time you reload the page, the puzzle starts with a new random ...