Решение задачи N3738 теория вероятностей Байеса

3738. The first machine handled 30 parts, 10 of them with defects, the second processed 40 parts, 5 of them with defects. On the third - 20 parts, from them 3 with defects. All parts are piled together; The item taken at random was free from defects. What is the probability that it is processed on the third machine?

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