A wire uses (1/5) of the full length for the first time, and (3/5) meters for the second time, exactly half of the wire is used twice. How many meters is this wire?
一根电线，第一次用去全长的(1/5)，第二次用去(3/5)米，两次正好用去这根电线的一半．原来这根电线长多少米？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<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">(1/2) - (1/5)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">(3/5) / (3/10)</gadget>
<output>2</output>

<result>2</result>