Решение задачи N5099 теория вероятностей

5099. There are 10 standard parts and 5 defective parts in a box. 3 pieces are drawn at random. What are the probabilities that among them: a) one is defective; b) two defective ones; c) at least one standard.

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