What fraction of (1/5) hour is (1/2) hour? What is the solution formula.
(1/5)小时是(1/2)小时的几分之几？解答算式是多少．
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/5) / (1/2)</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>