There are 2400 pencils in a box of 12 and a box of 20. How many boxes of these pencils are needed?
有2400只铅笔，每12只装一盒，每20盒装一箱，这些铅笔需要装多少箱？
<gadget id="calculator">2_400 / 12 / 20</gadget>
<output>10</output>

<result>10</result>