The 4 prisoners with white and black hats. Discover one of the most famous logical deduction exercises in the world
Os 4 prisioneiros com chapéus são tão famosos que viraram sinônimo de categoria. São os "Hat Puzzles" (Enigmas-Chapéu)
Discover the power of self-education and informal education on our website. Learn how to acquire new skills and knowledge on your own and develop your potential.
Recover your password.
A password will be e-mailed to you.