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
Compared to a person with white skin another person with dark skin will experience .
When an ant stings a person, it injects a liquid into the skin of the person which contains:
Two persons A,B have to speak at a function with 10 other persons.If the persons speak at random order,the probability that A speaks immediately before B is
Two persons are selected at random, from n persons seated in a row (n ge 3) . The probability that the selected persons are not seated consecutively, is equal to
Given four pair of gloves, they are distributed to four persons. Each person is given a right-handed and left-handed glove, then the probability that no person gets a pair is
