[tex] \displaystyle
\binom{n}{k} [/tex] is equal to the [tex](k+1) [/tex]th number in the [tex](n+1)[/tex]th line in Pascal's triangle.
So, [tex] \displaystyle
\binom{9}{3}[/tex] is equal to the 4th number in the 10th line in Pascal's triangle, which is 84.
