This book contains the problems and solutions of a famous Hungarian mathematics competition for high school students, from 1929 to 1943. The competition is the oldest in the world, and started in 1894. Two earlier volumes in this series contain the papers up to 1928, and further volumes are planned. The current edition adds a lot of background material which is helpful for solving the problems therein and beyond. Multiple solutions to each problem are exhibited, often with discussions of necessary background material or further remarks. This feature will increase the appeal of the book to experienced mathematicians as well as the beginners for whom it is primarily intended.