2015 Fermat Problem 11

Three-digit positive integers such as 789 and 998 use no digits other than 7, 8 and 9. In total, how many three-digit positive integers use no digits other than 7, 8 and 9?

\textbf{(A)}\ 36\quad \textbf{(B)}\ 6\quad \textbf{(C)}\ 9\quad \textbf{(D)}\ 18\quad \textbf{(E)}\ 27

If there are no answer choices shown, enter a numerical answer.

Full credit to this problem is given to the CEMC, you may view all Fermat contests here.