4669. There are products of four grades n1=2, n2=3, n3=3, n4=3. M items are taken at random to control. Determine the probability that among them m1=1 is first-class, m2=2, m3=3 and m4=1 of the second, 3rd and fourth grade, respectively.
Detailed solution. Decorated in Microsoft Word 2003 (Quest decided to use the formula editor)