TED-Ed

View full lesson: http://ed.ted.com/lessons/can-you-solve-the-river-crossing-riddle-lisa-winer As a wildfire rages through the grasslands, three lions and three wildebeest flee for their lives. To escape the inferno, they must cross over to the left bank of a crocodile-infested river. Can you help them figure out how to get across on the one raft available without losing any lives? Lisa Winer shows how. Lesson by Lisa Winer, animation by Artrake Studio.