Q.
A person invites a party of 10 friends at dinner and place them so that 4 are on one round table and 6 on the other round table. The number of ways in which he can arrange the guests is
Selection of 6 guests =10C6
Permutation of 6 on round table =5!
Permutation of 4 on round table =3
Then, total number of arrangements =10C6⋅5!⋅3!=6!⋅4!(10)!⋅5!⋅3! =24(10)!