For a bundle of wires, cut off the full length (2/5) for the first time, cut 20 meters for the second time, and cut off exactly half of the total length twice. How long is this bundle of wires in meters?
一捆电线，第一次剪去全长的(2/5)，第二次剪去20米，两次剪去的正好是全长的一半，这捆电线长多少米？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(1/2) - (2/5)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">20 / (1/10)</gadget>
<output>200</output>

<result>200</result>