Which one of the following is not equivalent to $0.000000375$? 
$\textbf{(A)}\ 3.75\times 10^{-7}\qquad\textbf{(B)}\ 3\frac{3}{4}\times 10^{-7}\qquad\textbf{(C)}\ 375\times 10^{-9}\qquad \textbf{(D)}\ \frac{3}{8}\times 10^{-7}\qquad\textbf{(E)}\ \frac{3}{80000000}$
First of all, $0.000000375 = 3.75 \times 10^{-7}$ in scientific notation. This eliminates $\textbf{(A)}\ 3.75\times 10^{-7}$, $\textbf{(B)}\ 3\frac{3}{4}\times 10^{-7}$, and $\textbf{(C)}\ 375\times 10^{-9}$ immediately. $\textbf{(E)}\ \frac{3}{80000000}$ is a bit harder, but it can be rewritten as $\frac{3}{8 \times 10^{7}} = \frac{3}{8} \times 10^{-7}$, which is the same as $\textbf{(D)}$. Thus, the answer is either $\textbf{(D)}$ or $\textbf{(E)}$.  The original contest had this error in it, although the desired answer was D.  It is likely that they intended option E to be $\frac{3}{8000000}$, but misprinted it.