The Academy of Fine Arts has a 3-story exhibition hall, with 4 exhibition halls on each floor. A total of 240 paintings are placed in these exhibition halls. How many paintings are placed in each exhibition hall on average?
美术学院有一个3层的展览馆，每层有4个展厅．在这些展厅里一共放了240幅画，平均每个展厅放几幅？
<gadget id="calculator">4 * 3</gadget>
<output>12</output>

<gadget id="calculator">240 / 12</gadget>
<output>20</output>

<result>20</result>