Respuesta :
We have been given that Nine wolves, eight female and one male, are to be released into the wild three at a time.
We need to choose 1 male wolf out of 1 wolf male. So we can choose one wolf as:
[tex]_{1}^{1}\textrm{C}[/tex]
[tex]\frac{1!}{1!(1-1)!}[/tex]
[tex]\frac{1!}{1!\cdot 0!}[/tex]
[tex]\frac{1}{1\cdot 1}=1[/tex]
We can choose 1 male wolf in only 1 way.
Since the female wolfs are identical (order doesn't matter), so we will use combinations.
We can choose 2 female wolves out of 8 as:
[tex]_{2}^{8}\textrm{C}[/tex]
[tex]\frac{8!}{2!(8-2)!}[/tex]
[tex]\frac{8\cdot 7\cdot 6!}{2\cdot 1\cdot 6!}=\frac{8\cdot7}{2}=28[/tex]
Therefore, we can choose 2 female wolves out of 8 female wolves in 28 ways.
To find number of ways in which the first group of three wolves can be formed we will multiply the ways of choosing 1 male wolf and 2 female wolves.
[tex]\text{Number of ways of forming first group of three wolves}=1\times 28=28[/tex]
Therefore, the first group of three wolves can be formed in 28 ways.