A cuboid with a height of 30cm is cut into two small cuboids along the horizontal direction. The surface area is increased by 80cm**2. What is the volume of the original cuboid?
一个长方体高30cm，沿着水平方向横向切成两个小长方体，表面积增加了80cm**2，原来长方体的体积是多少？
<gadget id="calculator">80 / 2</gadget>
<output>40</output>

<gadget id="calculator">40 * 30</gadget>
<output>1_200</output>

<result>1_200</result>