Several bearers carry three sedan chairs (4 people per sedan chair) to a place with a distance of 20 kilometers, and each bearer carries an average of 15 kilometers, so how many bearers are needed?
若干轿夫抬3顶轿(每顶轿4人抬)同到20千米路程的地方，平均每位轿夫抬15千米，那么需要轿夫多少个？
<gadget id="calculator">4 / 15</gadget>
<output>4/15 = around 0.266667</output>

<gadget id="calculator">20 * 3 * (4/15)</gadget>
<output>16</output>

<result>16</result>