Uncle Wang went from home to Zhongwei City to pull fertilizer. It took him 4 hours to travel 45 kilometers per hour, and 3 hours to return. How many kilometers per hour did he travel on average when he returned?
王叔叔从家去中卫城拉化肥，去时每小时行45千米，用了4小时，回来时用了3小时，返回时平均每小时行多少千米？
<gadget id="calculator">4 / 3</gadget>
<output>4/3 = around 1.333333</output>

<gadget id="calculator">45 * (4/3)</gadget>
<output>60</output>

<result>60</result>