十个人站成一列纵队,从十顶黄帽子和九顶蓝帽子中,取出十顶分别给每个人戴上。站在最后的第十个人说:“我虽然看见了你们每个人头上的帽子,但仍然不知道自己头上的帽子的颜色。你们呢?”第九个人说:“我也不知道。”第八个人说:“我也不知道。”第七个、第六个……直到第二个人 Ten people stand in a column, from the top ten yellow hat and nine blue hat, remove the top ten, respectively, to wear to everyone. The tenth man standing at the end said, “Although I have seen the hat of every one of you, I still do not know the color of the hat on my head.” What about you? “The ninth said,” I do not know either. “ Eighth person said: ”I do not know." Seventh, sixth ... Until the second person