It takes 5 hours for Li Qiang to copy a manuscript. This manuscript has been copied by others (1/4), and the rest is handed over to Li Qiang to copy, how many hours will it take to finish copying.
李强抄写一份稿件，需要5小时抄完．这份稿件已由别人抄了(1/4)，剩下的交给李强抄，还要用多少小时才能抄完．
<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 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(3/4) / (1/5)</gadget>
<output>15/4 = around 3.75</output>

<result>15/4 = around 3.75</result>