Решение задачи N3785 теория вероятностей полная вероятн

3785. In the box there are 10 parts of factory No. 1, 15 parts of factory No. 2, and 25 parts of factory No. 3. The probabilities that a high-quality item is respectively 0.95 for the first plant, 0.85 for the second and 0.7 for the third. Find the probability that a piece taken out of the box at random will be of high quality.

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