Решение задачи N4677 теория вероятностей

4677. There are products of four grades, and the number of products of each grade is, respectively, 2, 4, 5, 1. For control, 8 products are taken at random. Determine the probability that among them 2 is a first-class item, 2 is a second-grade item, 3 is a third-grade item, and 1 is a fourth-grade item.

Detailed solution. Decorated in Microsoft Word 2003 (Quest decided to use the formula editor)