a
\(\begin{array}{l}
Time\,taken\,if\,both\,moving\,in\,same\,direcation\\
\,\,\,\,\,\,\,\,\,\,\,\,{t_1} = \frac{{{\rm{distance}}}}{{speed}} = \frac{{0.12 + 0.06}}{{80 - 30}} = \frac{{0.18}}{{50}}\\
Time\,taken\,if\,moving\,in\,opposite\,direction\\
\,\,\,\,\,\,\,\,\,\,\,{t_2} = \frac{{{\rm{distance}}}}{{speed}} = \frac{{0.12 + 0.06}}{{80 + 30}} = \frac{{0.18}}{{110}}\\
\frac{{{t_1}}}{{{t_2}}} = \frac{{11}}{5}
\end{array}\)
