For a simple fraction, the denominator is reduced to (1/3) plus 1, and the numerator is expanded to 3 times plus 1 to get (7/10) (unreduced), then what is the fraction.
一个最简分数，分母缩小到(1/3)再加1，分子扩大到3倍再加1，得(7/10)(未约分)，则这个分数是多少．
<gadget id="calculator">7 - 1</gadget>
<output>6</output>

<gadget id="calculator">6 / 3 / 27</gadget>
<output>2/27 = around 0.074074</output>

<result>2/27 = around 0.074074</result>