The road from Guiyang to Changsha is 840km long. A car leaves Changsha for Guiyang at 9:00 in the morning and travels 60 kilometers per hour. When will it arrive in Guiyang?
贵阳到长沙的公路长840km，有一辆汽车上午9：00从长沙出发开往贵阳，每时行60千米，什么时间能到达贵阳？
<gadget id="calculator">840 / 60</gadget>
<output>14</output>

<gadget id="calculator">14 + 9</gadget>
<output>23</output>

<result>23</result>