A bundle of wires is used for the first time (1/5), and the second time is 15 meters longer than the first time, leaving exactly half. How long is this bundle of wires in meters?
一捆电线，第一次用去(1/5)，第二次比第一次多用15米，正好剩下一半，这捆电线长多少米？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

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

<gadget id="calculator">15 / (1/10)</gadget>
<output>150</output>

<result>150</result>