30C11 refers to:
[tex]30C11=\frac{30!}{11!(30-11)!}[/tex]Then,
[tex]\begin{gathered} 30C11=\frac{30!}{11!(30-11)!} \\ =\frac{30!}{11!\cdot19!}=\frac{30\cdot29\cdot28\cdot27\cdot26\cdot25\cdot24\cdot23\cdot22\cdot21\cdot20}{11!} \\ =64627300 \end{gathered}[/tex]Remember that, if n is a natural number:
[tex]n!=1\cdot2\cdot3\cdot\ldots\cdot n[/tex]Therefore, the answer is 54627300