Evaluate the following.
The notation $\left(\begin{array}{l}{n} \\ {r}\end{array}\right)$ means $\frac{n !}{r !(n-r) !} .$ For example
$$\left(\begin{array}{l}{5} \\{3}\end{array}\right)=\frac{5 !}{3 !(5-3) !}=\frac{5 !}{3 ! 2 !}=\frac{5 \cdot 4 \cdot 3 \cdot 2 \cdot 1}{(3 \cdot 2 \cdot 1) \cdot(2 \cdot 1)}=10$$
$$\left(\begin{array}{l}{8} \\{2}\end{array}\right)$$