Cut off a rope (1/5) and then connect it to 5 meters. It is shorter than the original (3/20). How many meters is the rope now?
将一根绳子先剪去(1/5)再接上5米后，比原来短(3/20)，现在绳子长多少米．
<gadget id="calculator">3 / 20</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">1 - (3/20)</gadget>
<output>17/20 = around 0.85</output>

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

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">(17/20) - (4/5)</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">5 / (1/20)</gadget>
<output>100</output>

<gadget id="calculator">100 * (17/20)</gadget>
<output>85</output>

<result>85</result>