A car travels from A to B. When I went there, the speed was 45 km/h, and it took 2 hours. When I came back, I pulled the goods and it took 3 hours. What was the average speed on the way back?
一辆汽车从甲地开往乙地．去的时候速度是45千米/小时，用了2小时．回来时拉了货，用了3小时．回来时平均速度是多少？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">45 * (2/3)</gadget>
<output>30</output>

<result>30</result>