There are four people in an airplane. They are as follows: \- The pilot (Obviously) \- The president of the USA \- The world's smartest man \- A student from a local school. ​ Suddenly, an alarm sounds. The pilot runs into the passenger cabin and says: "I don't want to alarm you, but there seems to be a problem with the engine. We're all going down!" The passengers and the pilot need to evacuate, but there's a problem: There are only three parachutes in the plane. One person has to stay behind. The president says, "I'm the president! My country needs me!" He grabs a parachute, puts it over his back and jumps out. The world's smartest man says, "I'm the world's smartest man! I must stay alive to show everybody my great, amazing inventions!" He grabs a bag from the same area where the president took his parachute, puts it over his back and jumps out. Now there are two passengers left, and seemingly only one parachute. "Well," the pilot says to the student, "I guess you can have the parachute. I suppose the captain goes down with his ship. "Actually," the student says. There is NOT one parachute, there are two!" The pilot is confused. "How come?" ​ "The world's smartest man jumped out with my school backpack!"