A truck drove from city A to city B, traveling 50 kilometers per hour, and it took 12 hours; when returning, the speed increased, and it took 10 hours. What is the speed of the truck when it returns?
一辆货车从甲城开往乙城，每小时行50千米，行驶了12小时；返回时速度提高了，用了10小时．货车返回时的速度是多少？
<gadget id="calculator">12 / 10</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">50 * (6/5)</gadget>
<output>60</output>

<result>60</result>