About the book: 2015 / This collection of riddles, erudition questions and logical problems is a real test of how flexible your mind is. This is a great opportunity to stimulate your brain, turn on logic, ingenuity, intuition and observation. They will help develop non-standard thinking, test erudition, and spend time usefully on vacation. Its compiler, Dmitry Chernyshev, maintains a blog dedicated to creative thinking (one of the most visited on the RuNet: more than 40,000 subscribers), and writes books on the same topic. For those who strive to think outside the box. For those who like to look for beautiful techniques for solving complex problems. For those who want to teach the same to their children.