There are two bamboo poles, long and short, and the length of the long pole is three times the length of the short pole. Insert them into the pond, the length inserted into the water is 40 centimeters, and the total length of the exposed part is 160 centimeters. May I ask: How many centimeters is the exposed length of the short bamboo pole?
有长、短两根竹竿，长竹竿的长度是短竹竿长度的3倍．将它们插入水塘中，插入水中的长度都是40厘米，而露出水面部分的总长为160厘米．请问：短竹竿露在外面的长度是多少厘米？
<gadget id="calculator">40 * 2</gadget>
<output>80</output>

<gadget id="calculator">80 + 160</gadget>
<output>240</output>

<gadget id="calculator">3 + 1</gadget>
<output>4</output>

<gadget id="calculator">240 / 4</gadget>
<output>60</output>

<gadget id="calculator">60 - 40</gadget>
<output>20</output>

<result>20</result>