The denominator of a fraction is 15, and after dividing it is (2/5), what is the original fraction.
一个分数的分母是15，约分后是(2/5)，这个分数原来是多少．
<gadget id="calculator">15 / 5 / 15</gadget>
<output>1/5 = around 0.2</output>

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

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