The solution of the equations 
\begin{align*}2x-3y &=7 \\ 4x-6y &=20\end{align*}
is: 
$\textbf{(A)}\ x=18, y=12 \qquad  \textbf{(B)}\ x=0, y=0 \qquad  \textbf{(C)}\ \text{There is no solution} \\  \textbf{(D)}\ \text{There are an unlimited number of solutions}\qquad \textbf{(E)}\ x=8, y=5$
$2x-3y=7\implies 4x-6y=14$
Then $4x-6y=14=20$, which is false, so there are no solutions; $\fbox{C}$