The distance from Xiao Ming's home to the city center is 140.4 kilometers, and it took 3 hours to go there, and it took an extra hour to return because of the rain. How many kilometers per hour is the speed of the vehicle going when going than the speed of returning when returning?
小明家到市中心的距离是140.4千米，去时用了3小时，返回时由于下雨，则多用了1小时．去时的车速比返回时的车速快多少千米/小时？
<gadget id="calculator">140.4 / 3</gadget>
<output>46.8</output>

<gadget id="calculator">3 + 1</gadget>
<output>4</output>

<gadget id="calculator">140.4 / 4</gadget>
<output>35.1</output>

<gadget id="calculator">46.8 - 35.1</gadget>
<output>11.7</output>

<result>11.7</result>