Tasks of the St. Petersburg School Math Olympiad 2020

The book is intended for schoolchildren, teachers, teachers of mathematical circles and just fans of mathematics. The reader will find in it the tasks of the St. Petersburg Olympiad of schoolchildren in mathematics of 2020.
All tasks are given with detailed solutions, the conditions and solutions of geometric problems are accompanied by drawings.
As an additional material, three tales about the adventures of the bead are given: in the first, Python studies in the first Busenka, simultaneously inventing a way of graphic solution of arbitrary polynomial equations, in the second she helps a colleague with a spruden to find out if there are unspoiled goods in his store, and in The third talks about the basics of the theory of fuzzy sets