http://nautil.us/blog/the-simple-logical-puzzle-that-shows-how-illogical-people-are
"Wason tells you that if a card shows an even number on one face, then its opposite face is blue. Which cards must you turn over in order to test the truth of his proposition, without turning over any unnecessary cards? Click on your answer in the interactive video below:"
"Wason tells you that if a card shows an even number on one face, then its opposite face is blue. Which cards must you turn over in order to test the truth of his proposition, without turning over any unnecessary cards? Click on your answer in the interactive video below:"