In a bar chart, if 30 people are represented by 1 cm long bars, how many centimeters should be used to represent 120 people.
在一个条形统计图中，如果用1厘米长的直条表示30人，那么应该用多少厘米长的直条表示120人．
<gadget id="calculator">120 / 30</gadget>
<output>4</output>

<result>4</result>