трёх

трёх

"Трёх" means "three" (genitive or prefix form).

Here, 'трёх' is used as the genitive plural form of 'three', indicating 'out of three'.

Я купил три книги, три ручки, и из них выбрал три из трёх для работы.

I bought three books, three pens, and chose three out of three for work.

In this sentence, 'трёх' serves as the genitive case to define 'three groups'.

Эксперимент прошёл успешно благодаря участию трёх групп специалистов.

The experiment was successful thanks to the participation of three groups of specialists.

This use of 'трёх' highlights selection or description of 'three of them', employing the word in a genitive plural context.

Посетители осмотрели три выставки и записали свои впечатления о трёх из них.

The visitors viewed three exhibitions and recorded their impressions of three of them.