An interesting TEd talk by Judd A. Schorr who challenges your mind. Over 700.000 views for this riddle, that sounds a lot like a text exam in math. Can you solve it?
“Professor Fukanō, the famous scientist, has embarked on a new challenge – piloting around the world in a plane of his own design. There’s just one problem: there’s not enough fuel to complete the journey. Luckily, there are two other planes to help. Can you help the professor fly for the whole trip and achieve his dream, without anyone running out of fuel and crashing?”