A professor wished to figure out who was the smartest of his graduate students. He brought them into his office, blindfolded them, covered all the mirrors in the room, and sat them in chairs facing one another. He told them that he would put either a yellow or a green hat on their heads, but then placed, on all three students, a small green hat (representing Creativity from De Bono's Six Thinking Hat Colors) and no yellow ones! He then told them to remove their blindfolds and to look at one another, but not their own heads. He asked "raise your hand if you see a green hat" to which all three raised a hand. Next, he said "stand up if you know the color of the hat on your head." After a lengthy pause, only one student stood up and correctly stated the color of all three hats was green. How was this known? Outline your logic. This one took me about 15 minutes to figure out using a lot of "outside the box" thinking.