Решение задачи N5077 теория вероятностей

5077. In a batch of finished products, consisting of 20 parts, 3 are defective. Determine the probability that, given a random selection of four products at the same time, all of them will be defective. What is the probability that there will be an equal number of defective and non-defective products?

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