Eggs and duck eggs are 500 kg in total, and each 5 kg is packed in a carton. Among them, eggs are packed in 40 cartons. How many cartons are packed in duck eggs?
鸡蛋和鸭蛋共500千克，每5千克装一箱，其中鸡蛋装了40箱，鸭蛋装多少箱？
<gadget id="calculator">5 * 40</gadget>
<output>200</output>

<gadget id="calculator">500 - 200</gadget>
<output>300</output>

<gadget id="calculator">300 / 5</gadget>
<output>60</output>

<result>60</result>