Bakayev E.V.

In a circle, there are boys and girls (both are present), a total of 20 children. It is known that for each boy, the neighbor in the clockwise direction is a child in a blue T-shirt, and for each girl, the neighbor in the counterclockwise direction is a child in a red T-shirt. Can the number of boys in the circle be determined unambiguously?
The MHD (clockwise) arrangement cannot be due to the color of child X's T-shirt. Therefore, one boy should stand clockwise from the boy, one boy from him, and so on. This means that there are no fewer than half of all the children in the circle who are boys. By similar considerations, there are no fewer than half of the girls. Therefore, there are 10 boys and 10 girls.

## Answer

It can be.