A rope is used (1/4), and then 15 centimeters are connected. At this time, it is shorter than the original one (1/6). What is the original length of the rope in centimeters?
一根绳子，用去(1/4)，又接上15厘米，这时比原来短了(1/6)，这根绳子原来长多少厘米．
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

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

<gadget id="calculator">1 - (1/4)</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">1 - (1/6) - (3/4)</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">15 / (1/12)</gadget>
<output>180</output>

<result>180</result>