1. A square of size $2019 \times 2019$ is divided by two horizontal and two vertical lines into 9 rectangles. The sides of the central rectangle are 1511 and 1115. Find the sum of the areas of the corner rectangles.
1. Answer: 508*904. Solution. Notice that the corner rectangles form a rectangle $508 * 904$.

Grading criteria. Correct solution - 7 points. It is shown that a rectangle is formed, but there is an inaccuracy in the calculations - $\mathbf{4}$ points. One of the specific cases of partitioning is discussed - 0 points.