The railway workers want to change the track, and replace the original 6-meter-long old track with each 9-meter-long old track. A total of 240 new tracks are replaced. How many old tracks are replaced? (Solve with ratio)
铁路工人要换轨道，用每根9米的新轨道替换原来每根长6米的旧轨道，共换上新轨道240根，换下的旧轨道是多少根？(用比例解)
<gadget id="calculator">240 / 6</gadget>
<output>40</output>

<gadget id="calculator">9 * 40</gadget>
<output>360</output>

<result>360</result>