It took (1/5) hours for A to complete (2/3) of a job alone, how many hours will it take if all of them are completed?
一件工作，甲先单独完成(2/3)用了(1/5)小时，如果全完成，要用多少小时．
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(1/5) / (2/3)</gadget>
<output>3/10 = around 0.3</output>

<result>3/10 = around 0.3</result>