For the first $$\frac{3}{4}$$ of the journey, a bus driver drove at a speed of 50 $$km/h$$.<br>For the remaining 20 $$km$$ of the journey, he drove at a speed of 80 $$km/h$$.<hr>How long did he take to drive the last 20 $$km$$ of the journey? <br> <input min="0" type="number" id ="imp6pg168q7a_1" class="lineinput" placeholder="?" /> $$min$$