Answer:
126 groups
Step-by-step explanation:
we know that
This is a combination problem, because the order doesn't matter. He has 9 toys and wants to know the number of different combinations of 5 he can take.
The formula for the number of possible combinations of r objects from a set of n objects is given by
[tex]^nC_r=\frac{ {n!}}{r!(n-r)!}[/tex]
In this problem we have
[tex]n=9, r=5[/tex]
substitute
[tex]^9C_5=\frac{ {9!}}{5!(9-5)!}[/tex]
[tex]^9C_5=\frac{ {9!}}{5!(4)!}[/tex]
[tex]^9C_5=\frac{ {(9)(8)(7)(6)5!}}{5!(4)!}[/tex]
[tex]^9C_5=\frac{ {9)(8)(7)(6)}}{(4*3*2*1)}[/tex]
[tex]^9C_5=126[/tex]