Искусство и логика счёта: перестановки, комбинации и принципы счёта

The Art and Logic of Counting develops permutations and combinations as a system of logical reasoning rather than a collection of formulas. Beginning with fundamental counting principles, the book builds a structured approach to arrangements, selections, overcounting, complementary counting, and symmetry-based arguments. Emphasis is placed on understanding why counting methods work and how to apply them flexibly to unfamiliar problems. The book progresses from elementary ideas to advanced counting techniques commonly used in probability, algebra, and Olympiad mathematics. Strategy, structure, and method-driven thinking are emphasized throughout, helping readers develop confidence in combinatorial problem solving. This book is written for high achievers in IB, AP, and A-Level mathematics, advanced secondary students, Olympiad aspirants, and learners aiming for the world’s top universities, where strong logical reasoning and mathematical maturity are essential. This volume forms the foundation of the Math By Rishabh Series and prepares readers for further study in probability, statistics, and discrete mathematics.