The three classes of the third grade earned a total of 540 yuan from selling waste paper and mineral water bottles last semester. How much is the average income of each class?
三年级3个班上学期卖废纸和矿泉水瓶一共收入540元，平均每个班收入多少元？
<gadget id="calculator">540 / 3</gadget>
<output>180</output>

<result>180</result>