h: " n persons are seated on n chairs at a round table. Find the probability that two specified persons are sitting next to each other.i: Twenty books are placed at random in a shelf. Find the...

h: " n persons are seated on n chairs at a round table. Find the probability that two specified persons are sitting next to each other. i: Twenty books are placed at random in a shelf. Find the probability that a particular of books shall be: (i) Always together (ii) Never together.