This book is part of a five-volume series, with the other volumes focusing on geometry and trigonometry, algebra, numbert theory, and calculus. Each volume is dedicated to a fundamental branch of mathematics, providing learners with a well-rounded foundation in problem-solving techniques essential for mathematical competitions and advanced studies as well as world-class mathematical training, featuring a carefully curated collection of challenging and thought-provoking problems. Through this book, students will refine their analytical skills, develop creative problem-solving techniques, and gain confidence in tackling complex mathematical challenges.