The school bought two tug-of-war ropes, one 30 meters long and the other 15 meters long. After cutting off a section of the same length from the two tug-of-war ropes as needed, the remaining length of the short tug-of-war rope is the remaining length of the long tug-of-war rope. For the next (2/5), how long is the same length of tug-of-war rope cut off?
学校买来两根拔河绳，一根长30米，另一根长15米，根据需要从两根拔河绳上各剪去同样长的一段后，短拔河绳剩下的长度是长拔河绳剩下的(2/5)，剪去的同样长的这一段拔河绳子有多长？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(2/5) * 30</gadget>
<output>12</output>

<gadget id="calculator">15 - 12</gadget>
<output>3</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">3 / (3/5)</gadget>
<output>5</output>

<result>5</result>