In the activity of collecting tree species for greening the motherland, there are 5 classes in the fourth grade of a certain school, each class collects 20 kilograms of tree species, and 3 classes in the fifth grade collect a total of 60 kg. How many kilograms of tree species are collected on average in each class?
在绿化祖国采集树种的活动中，某校四年级5个班级，每班采集树种20千克，五年级3个班共采集60千克，平均每班采集树种多少千克？
<gadget id="calculator">20 * 5</gadget>
<output>100</output>

<gadget id="calculator">100 + 60</gadget>
<output>160</output>

<gadget id="calculator">5 + 3</gadget>
<output>8</output>

<gadget id="calculator">160 / 8</gadget>
<output>20</output>

<result>20</result>