Решение задачи N4693 теория вероятностей полиномиальный

4693. For each lottery ticket with probability p1=0.15 there may be a big win, with probability p2=0.2 - a small win, and with probability p3=0.65 the ticket may be without a win. Bought n=15 tickets. Determine the probability of getting n1=2 big wins and n2=2 small ones.

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