In the "Sunshine Sports Activities for Primary and Secondary School Students", the students in Class 3, Grade 5 first ran for 20 minutes at a speed of 0.18 kilometers per minute, and then ran for 30 minutes at a speed of 0.16 kilometers per minute. What is the average running speed of the students in this activity?
在"中小学生阳光体育活动"中，五年级三班的同学先以每分钟0.18千米的速度跑了20分钟，又以每分钟0.16千米的速度跑了30分钟．同学们在这次活动中跑步的平均速度是多少？
<gadget id="calculator">20 * 0.18</gadget>
<output>3.6</output>

<gadget id="calculator">30 * 0.16</gadget>
<output>4.8</output>

<gadget id="calculator">3.6 + 4.8</gadget>
<output>8.4</output>

<gadget id="calculator">20 + 30</gadget>
<output>50</output>

<gadget id="calculator">8.4 / 50</gadget>
<output>0.168</output>

<result>0.168</result>