A piece of iron wire is 40 meters long, cut off the full length (2/5) for the first time, cut off the first (3/4) for the second time, how many meters are cut off for the second time?
一根铁丝长40米，第一次剪去全长的(2/5)，第二次剪去第一次的(3/4)，第二次剪去多少米？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">40 * (2/5) * (3/4)</gadget>
<output>12</output>

<result>12</result>