Before you is a collection by Lewis Carroll, well known to children and parents in perhaps all countries, the author of exciting books about Alice’s adventures. However, not everyone knows that Carroll was also an outstanding mathematician. His mathematical works remained unknown to readers for a long time. In this book, Carroll appears to us in the role of a faultless mathematician and logician. Here you will find entertaining mathematical puzzles, engaging problems, and elegant paradoxes. You can make good use of your leisure time, develop your logic, attentiveness, and imagination.