Description for Correct answer:
\( \Large v_{1} \) + \( \Large v_{2} \) = \( \Large \frac{10}{1} \) = 10 ...(i)

\( \Large v_{1} \) - \( \Large v_{2} \) = \( \Large \frac{14}{2} \) = 7 ...(ii)

Adding equations (i) and (ii), we get

\( \Large v_{1} \) = \( \Large \frac{17}{2}km/hr \)

\( \Large t = \frac{d}{v_{1}} = \frac{17}{\frac{17}{2}} \) = 2 hrs.