12 persons are seated at a round table. Number of ways of selecting 2 persons not adjacent to each other is

12persons are seated at a round table. Number of ways of selecting 2persons not adjacent to each other is

14 persons are seated at a round table. Find the number of ways of selecting two persons out of them who are not seated adjacent to each other.

10 persons are seated at round table then the number of ways of selecting 3 persons out of them if no two persons are adjacent to each other is

If n persons are sitting in a row, find the number of ways of selecting two persons, who are sitting adjacent to each other.

The number of ways in which 7 persons can be seated at a round table if twom particular persons are not to sit together is

10 persons are sitting in a row. Find the number of ways of selecting two persons out of them who are sitting adjacent to each other

Ten persons are arranged in a row . The number of ways of selecting four persons so that no two persons sitting next to each other's are selected is