40 pears are allocated to 3 classes, 20 are allocated to the first class, and the rest are evenly distributed to the second and third classes. How many pears are assigned to the second class.
40个梨分给3个班，分给一班20个，其余平均分给二班和三班，二班分到多少个．
<gadget id="calculator">40 - 20</gadget>
<output>20</output>

<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<result>10</result>