The number of ways in which 9 persons can be divided into three equal groups is

The total number of ways in which 12 persons can be divided into three groups of 4 persons each, is

The total number of ways in which 2n persons can be divided into n couples is

The total number of ways in which 2n persons can be divided into n couples is

The number of ways in which 12 students can be equally divided into three groups is

The number of ways in which 12 students can be equally divided into three groups is

To find the number of ways in which m+n+p things can be divided into three groups containing m,n,p things severally.

Total number of ways in which “2n' persons can be divided into ‘n’ couples is

The number of ways in which 12 people may be divided into three sets of equal size is

The number of ways in which 4n things can be divided into 4 equal parts is