One of the downsides of how we learn math in high school is that many of us come to believe that if we cant solve a problem in ten or twenty minutes,...

One of the downsides of how we learn math in high school is that many of us come to believe that if we cant solve a problem in ten or twenty minutes, then we cant solve it at all. There will be problems in this book that take hours of hard thought. Many of these problems were rst conceived and solved by professional mathematicians, and they spent days or weeks on them. How can you be expected to solve them at all then?