• question_answer 12 persons are to be arranged to a round table. If two particular persons among them are not to be side by side, the total number of arrangements is [EAMCET 1994] A) $9(10\ !)$ B) $2(10\ !)$ C) $45(8\ !)$ D) $10\ !$

12 persons can be seated around a round table in $11\ !$ ways. The total number of ways in which 2 particular persons sit side by side is$10\ !\ \times \ 2\ !$. Hence the required number of arrangements$=11\ !\ -10\ !\ \times 2\ !\ =9\times 10\ !$.