The bilingual primary school organizes sixth graders to conduct field training. They walked a total of 11 kilometers in the first 2 hours and 3 kilometers per hour in the last 3 hours. How many kilometers per hour do the sixth graders walk on average?
双语小学组织六年级学生进行野外训练，前2个小时共走了11千米，后3个小时每小时走3千米，六年级学生平均每小时走多少千米？
<gadget id="calculator">3 * 3</gadget>
<output>9</output>

<gadget id="calculator">11 + 9</gadget>
<output>20</output>

<gadget id="calculator">2 + 3</gadget>
<output>5</output>

<gadget id="calculator">20 / 5</gadget>
<output>4</output>

<result>4</result>