Решение задачи N5320 теория вероятностей

5320. From a batch in which 30 parts without defects and 5 with defects, 3 parts are taken at random. Determine the probability that: 1) all three parts are free of defects; 2) at least one item without defects?

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