A cuboid has a length of 20 cm and a height of 15 cm. The height is reduced by 3 centimeters and the surface area is reduced by 180 square centimeters. What is the width of the cuboid in centimeters?
一块长方体长是20厘米、高是15厘米．高减少3厘米，表面积减少180平方厘米．长方体的宽是多少厘米？
<gadget id="calculator">180 / 3</gadget>
<output>60</output>

<gadget id="calculator">60 / 2</gadget>
<output>30</output>

<gadget id="calculator">30 - 20</gadget>
<output>10</output>

<result>10</result>