Решение задачи N5322 теория вероятностей

5322. From a batch in which 34 parts without defects and 6 with defects, 3 parts are taken for good luck. What is the probability that there will be:
a) all 3 parts without defects;
b) at least one part without defects?

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