The sum of the numerator and denominator of a fraction is 98. After simplifying the fraction, it is (2/5). What is the fraction?
一个分数分子与分母的和是98，把这个分数化简后是(2/5)，这个分数是多少．
<gadget id="calculator">2 + 5</gadget>
<output>7</output>

<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">98 * (5/7)</gadget>
<output>70</output>

<gadget id="calculator">(2/7) / 70</gadget>
<output>1/245 = around 0.004082</output>

<gadget id="calculator">98 * (1/245)</gadget>
<output>2/5 = around 0.4</output>

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