A truck loads goods from City A to City B at a speed of 65 km/h, arrives in City B in 4 hours, and takes 5 hours to return. How many kilometers per hour does the truck travel on average when it returns?
货车以65千米/时的速度从甲城往乙城装货物，4小时到乙城，回来用了5小时，货车回来时平均每小时行多少千米？
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">65 * (4/5)</gadget>
<output>52</output>

<result>52</result>