Uncle Li drove from the county seat to Wangzhuang to deliver fertilizers. When he went there, he traveled 40 kilometers per hour and arrived in 3 hours. When he returned, he only took 2 hours. How many kilometers per hour did he travel on average when he returned?
李叔从县城开车去王庄送化肥，去时每小时行40千米，3小时到达，返回时只用了2小时，返回时平均每小时行多少千米？
<gadget id="calculator">3 / 2</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">40 * (3/2)</gadget>
<output>60</output>

<result>60</result>