It is an uphill road from City A to City B. It takes 3 hours to go by car at a speed of 30 km/h, and it takes 2 hours to return. What speed was it when it came back?
从甲城去乙城是上坡路，汽车去时用了3小时，速度为30千米/时，回来时用了2小时．回来时的速度是多少？
<gadget id="calculator">3 / 2</gadget>
<output>3/2 = around 1.5</output>

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

<result>45</result>