A person rides a bicycle from point A to point B. He travels 3 km at 0.2 hours at the beginning, and travels the rest of the way at a speed of 0.3 km per minute for 18 minutes. What is the average speed of this person cycling from A to B in kilometers per hour?
某人骑自行车从甲地至乙地，开始时0.2时行了3km，剩下的路又以每分钟0.3km的速度行了18分钟．这个人从甲地到乙地骑自行车的平均速度是每小时多少千米？
<gadget id="calculator">18 * 0.3</gadget>
<output>5.4</output>

<gadget id="calculator">3 + 5.4</gadget>
<output>8.4</output>

<gadget id="calculator">0.2 + 0.3</gadget>
<output>0.5</output>

<gadget id="calculator">8.4 / 0.5</gadget>
<output>16.8</output>

<result>16.8</result>