Three different objects, 1, 2, and 3, are distributed at random on three different sites, marked 1,2, 3. The event is: (a) none of objects occupies the place corresponding to its number; (b) at least...

Three different objects, 1, 2, and 3, are distributed at random on three

different sites, marked 1,2, 3. The event is: (a) none of objects occupies

the place corresponding to its number; (b) at least two of the objects