A and B stand in a ring with 10 other persons. If the arrangement of the persons is at random, then the probability that there are exactly 3 persons between A and B is

A and B stand in a ring with 10 other persons . If the arrangement of the twelve persons is at random , find the chance that there are exactly three persons between A and B.

A and B stand in a ring with 10 other persons . If the arrangement of the twelve persons is at random , find the chance that there are exactly three persons between A and B.

A and B stand in a ring with 10 other persons . If the arrangement of the twelve persons is at random , find the chance that there are exactly three persons between A and B.

A and B stand in a ring along with 10 other pèrsons. If the arrangement is at random, the probability that there are exactly 3 persons between A and B , is

A and B are among 20 persons sit at random along a round table. Find the probability that there are any 6 persons between A and B.

Fifteen person, among whom are A and B , sit down at random at a round table, the probability that there are exactly are 4 persons between A and B is