The ratio of length to width of a rectangle is 5:2, and the length is 20 cm. What is the ratio of width to length in cm?
一个长方形长与宽的比例是5：2，长是20厘米，宽比长短多少厘米．
<gadget id="calculator">20 / 5</gadget>
<output>4</output>

<gadget id="calculator">5 - 2</gadget>
<output>3</output>

<gadget id="calculator">4 * 3</gadget>
<output>12</output>

<result>12</result>