There is a ribbon, 25% of the total length is used for the first time, and 2/5 of the full length is used for the second time. The first time is 18 cm less than the second time. What is the total length of this ribbon in cm? ．
有一根丝带，第一次用去全长的25%，第二次用去全长的(2/5)，第一次用去的比第二次少18厘米，这根丝带全长多少厘米．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(2/5) - (1/4)</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">18 / (3/20)</gadget>
<output>120</output>

<result>120</result>