If five identical cubes are put together to form a cuboid, and the surface area is reduced by 40 m2, what is the surface area of each original cube?
把5个完全一样的正方体拼成一个长方体，表面积减少40㎡，则原来每个正方体的表面积是多少㎡．
<gadget id="calculator">40 / 8</gadget>
<output>5</output>

<gadget id="calculator">5 * 6</gadget>
<output>30</output>

<result>30</result>