A cuboid is spliced with a cube with an edge length of 5 cm to form a new cuboid. The surface area of the new cuboid is 310 cm. What is the length of the original cuboid?
一个长方体，拼接上一个棱长5厘米的正方体，组成新的长方体，新长方体的表面积是310厘米，原来长方体的长是多少？
<gadget id="calculator">5 * 5 * 2</gadget>
<output>50</output>

<gadget id="calculator">310 - 50</gadget>
<output>260</output>

<gadget id="calculator">5 * 4</gadget>
<output>20</output>

<gadget id="calculator">260 / 20</gadget>
<output>13</output>

<gadget id="calculator">13 - 5</gadget>
<output>8</output>

<result>8</result>