Known fraction sequence: (1/1), (7/8), (5/6), (13/16), (4/5), (19/24), you know the 20th fraction of this sequence how many.
已知分数列：(1/1)，(7/8)，(5/6)，(13/16)，(4/5)，(19/24)，你知道这个数列的第20个分数是多少．
<gadget id="calculator">20 - 1</gadget>
<output>19</output>

<gadget id="calculator">3 * 19</gadget>
<output>57</output>

<gadget id="calculator">4 + 57</gadget>
<output>61</output>

<gadget id="calculator">19 * 4</gadget>
<output>76</output>

<gadget id="calculator">4 + 76</gadget>
<output>80</output>

<gadget id="calculator">61 / 80</gadget>
<output>61/80 = around 0.7625</output>

<result>61/80 = around 0.7625</result>