After a vegetable truck was loaded with 8 tons of vegetables from the wholesale market in Lijia Town, Anshan, it drove for 7.5 hours at an average speed of 40 kilometers per hour and arrived at Dalian Dacai Market. After unloading the vegetables, the truck returned and took 5 hours. What is the average speed of the truck on the return trip? (answered in two different ways)
一辆运菜货车从鞍山李家镇批发市场装满8吨蔬菜后，以平均每小时40千米的速度行驶了7.5时，到达大连大菜市．卸下菜后，货车返程，用了5时．货车返程时的平均速度是多少？(用两种不同的方法解答)
<gadget id="calculator">7.5 / 5</gadget>
<output>1.5</output>

<gadget id="calculator">40 * 1.5</gadget>
<output>60</output>

<result>60</result>