The army was considering putting on additional armor to increase the survival chances of their planes. The question was: where to put it? You can’t put it everywhere — the plane won’t leave the ground then.
What would you do? Given what you know about airplanes, what part of the plane would you equip with more armor? Don’t rush. Take a couple of minutes.
The story goes as follows: The army wanted to figure out exactly how much armor belonged on parts A, B, and C of the plane. That was the question they asked Abraham Wald — a statistician from Columbian University. The answer surprised them quite a lot.