Решение задачи N2833 теория вероятностей

2833. In a group of 25 students. Of these, 3 people perfectly wrote the test, 5 people wrote well, 10 people satisfactorily, the rest wrote a test paper unsatisfactory. Find the probability that among the five students called to the blackboard, three received unsatisfactory on the test paper.

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