In the system of equation below $a$ and $b$ are constant . If it has no solution, What is the value of $\Large\frac{a}{b} +\frac{1}{4} $<br><br>$\qquad \qquad \qquad ax-by=10, \\\qquad \qquad \qquad x+4y=20.$

Question

$\begin{array}{1 1} a)\;0 \\ b)\;-1 \\ c)\;1 \\ d)\;\large \frac{1}{2} \end{array} $