Railway workers renovate the railway and replace the original 6-meter-long old rails with new 9-meter-long rails. A total of 240 new rails are replaced. How many old rails are replaced?
铁路工人整修铁路，用每根长9m的新铁轨替换原来每根长6m的旧铁轨，共换上新铁轨240根，换下的旧铁轨是多少根？
<gadget id="calculator">240 / 6</gadget>
<output>40</output>

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

<result>360</result>