5:42

Can you solve Dongle's Difficult Dilemma? - Dennis E. Shasha

5:07

Can you solve the giant spider riddle? - Dan Finkel

5:38

The Mathematical Secret Hidden in the Word Most

12:23

Even the Smartest Professor Can't Solve All 17 Riddles

6:17

Can you solve the private eye riddle? - Henri Picciotto