Решение задачи N5078 теория вероятностей

5078. In a batch of finished products, consisting of 25 parts, 5 defective ones. Determine the probability that with a random choice of four parts: a) all will be defective; b) defective and non-defective products will be equally divided.

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