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>What was the average speed of the bus? Giveyour answer correct to 1 decimal place.<br> <input min="0" type="number" id ="imp6pg168q7c_1" class="lineinput" placeholder="?" /> $$km/h$$