The school teaching building has 4 floors, 5 classrooms on each floor, and a total of 120 fluorescent lamps, how many fluorescent lamps are installed in each classroom on average.
学校教学楼有4层，每层5间教室，共装120盏日光灯，平均每间教室安装多少盏日光灯．
<gadget id="calculator">120 / 4 / 5</gadget>
<output>6</output>

<result>6</result>