Student: If six persons sit in a row, then the probability that three particular persons are always together is -.
Options:
(A) 1/5
(B) 1/7
(C) 1/9
(D) 1/2
(E) 2/7.
Another student: Let's say, hmmm...
3!4! Required probability = 3!4!/6! = 1/5 Final answer: (A).