The number of ways in which 10 boys can take positions around a circular round table, if two particular boys must not be seated side by side, is

Step-by-step solution

Total number of ways without any restriction = 9 ! Considering two of the particular boys sit together and then assuming them as one, the total no. of ways = 8 ! They them selves can be arranged in 2 ways. So, the required number of ways = 9 ! - 2 × 8 ! = 7 × 8 !