Answer
$C(8,6) = 28$
Work Step by Step
Use the formula $C(n, r)=\dfrac{n!}{(n-r)!r!}$:
$C(8,6)
\\= \dfrac{8!}{(8-6)!6!}
\\= \dfrac{8!}{2!\times 6!}
\\= \dfrac{8\times7\times6!}{2! \times 6!}
\\= \dfrac{8\times7}{2!}
\\=\dfrac{56}{2}
\\=28$