Meenashee cycles to her school at an average speed of $12\;km/hr$ and takes $20 $ minutes to reach her school. If she wants to reach her school in $12$ minutes , her average speed should be

Question

$\begin{array}{1 1} \frac{20}{3}\;km/hr \\ 16\;km/hr \\ 20\;km/hr \\ 15\;km/hr \end{array} $