The ratio of the length to the width of a rectangle is 4:3, the known length is 20 meters, and how many meters is the width.
一个长方形的长与宽的比是4：3，已知长是20米，宽是多少米．
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">20 * (3/4)</gadget>
<output>15</output>

<result>15</result>