Решение задачи N3713 теория вероятностей Байеса

3713. Two punchers filled in the same set of punched cards. The probability that the first puncher makes a mistake is 0.2; for the second puncher, this probability is 0.3. An error was found when checking the punched cards. Find the probability that the second puncher was mistaken.

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