Решение задачи N3737 теория вероятностей Байеса

3737. On the first machine, 20 parts were processed, 7 of them with a defect, 30 parts on the second, 4 of them are with defects, 50 are on the third, 10 of which are with defects. All parts are piled together. A piece 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)