One day you were captured by the Taliban and left to die in the desert. You find a Jeep with 1 gallon of fuel in it. When you look around you perceive two oases one to the left and one to the right. The only chance of your survival is to go to one or the other of the oases. One of the two places is a mirage. The amount of gas that it takes to get to each oasis is half a gallon, what do you do?
(Answer at bottom of the page)
You go 1/4 of the way to one of the oases to check if it is a mirage. You know a mirage because it seems to go away from you. Then if it is a mirage you go to the other oasis with the rest of the fuel.