Calculation: (((1/2)+(1/4)+(1/6)+(1/8))-((1/3)+(1/6)+(1/9)+(1 /12)))/(((1/4)+(1/8)+(1/12)+(1/16))-((1/5)+(1/10)+(1/5 )+(1/20))).
计算：(((1/2)+(1/4)+(1/6)+(1/8))-((1/3)+(1/6)+(1/9)+(1/12)))/(((1/4)+(1/8)+(1/12)+(1/16))-((1/5)+(1/10)+(1/5)+(1/20)))．
<gadget id="calculator">1 / 72</gadget>
<output>1/72 = around 0.013889</output>

<gadget id="calculator">1 / 480</gadget>
<output>1/480 = around 0.002083</output>

<gadget id="calculator">(1/72) / (1/480)</gadget>
<output>20/3 = around 6.666667</output>

<result>20/3 = around 6.666667</result>