Seema cycles to her school at an average speed of $12\;km/hr$ It takes her 20 min to reach the school. If she wants to reach school in 15 mins , What will be her average speed.

Question

$\begin{array}{1 1} 16\;km/hr \\ 12\;km/hr \\ 10\;km/hr \\ 18\;km/hr \end{array} $