5 persons A,B,C,D and E occupy seats in a row at random. What is the probability that A and B sit next to each other ?  Choices:	A) 3/5	B) 2/5	C) 1/5	D) 8/5	E) None of these
Explanation :   Without restriction, number of arrangements = 5! .   =&gt; Number of possible outcomes = T = 5! = 120 .   With restriction, number of arrangements = 4! x 2 .   ( i.e considering A and B together) = 48.   =&gt; Number of favourable outcomes = F = 48.   Hence,   P( A and B sit together)   =&gt; F / T   =&gt; No. of arrangements with restriction / No. of arrangements without restriction .   =&gt; 48 / 120.   =&gt; 2 / 5.   Answer : 2/5
<result>B</result>
5 persons A,B,C,D and E occupy seats in a row at random. What is the probability that A and B sit next to each other ?