If the numerator of a fraction is reduced by 10 times and the denominator is enlarged by 10 times, it is (3/40), what is the original fraction?
一个分数的分子缩小10倍，分母扩大10倍后是(3/40)，原来的分数是多少．
<gadget id="calculator">3 * 10</gadget>
<output>30</output>

<gadget id="calculator">40 / 10</gadget>
<output>4</output>

<gadget id="calculator">30 / 4</gadget>
<output>15/2 = around 7.5</output>

<result>15/2 = around 7.5</result>