Answer:
84
Step-by-step explanation:
To find this, we need to understand the combination formula.
If we have n items and we want to choose r at a time, we use the formula:
[tex]nCr=\frac{n!}{(n-r)!*r!}[/tex]
Where n! means n(n-1)(n-2)....
So we want 9C3, plugging them into the formula and doing some arithmetic, we have:
[tex]nCr=\frac{n!}{(n-r)!*r!}\\9C3=\frac{9!}{(9-3)!*3!}\\=\frac{9!}{6!*3!}\\=\frac{9*8*7*6!}{6!*3*2*1}\\=\frac{9*8*7}{3*2*1}\\=84[/tex]
So, there can be 84 combinations possible.
