In how many ways can 5 friends of a man be seated on a round table and 4 friends on other round table out of 9 friends?

Explanation

No. of ways of selecting 5 friends out of 9 friends `= .^(9)C_(5)`.
`:.` Remaining friends in 2nd group = 4 No. of ways of arranging 5 friends on 1st round table `= (5-1)! = 4! = 24`
No. of ways of arranging 4 friends on 2nd round table `= (4-1)! = 3! = 6`
From multiplication theorem Required ways `= .^(9)C_(5) xx 24 xx 6 = 18144`.