Can you solve the frog riddle? - Derek Abbott
View full lesson: http://ed.ted.com/lessons/can-you-solve-the-frog-riddle-derek-abbott You're stranded in a rainforest, and you've eaten a poisonous mushroom.
Can you solve the temple riddle? - Dennis E. Shasha
View full lesson: http://ed.ted.com/lessons/can-you-solve-the-temple-riddle-dennis-e-shasha Your expedition finally stands at the heart of the ancient temple.