For a fraction, the result of adding 1 to the numerator is (1/2), and the result of adding 2 to the denominator is (1/3). What is this fraction?
一个分数，分子加1结果是(1/2)，分母加2结果是(1/3)，这个分数是多少？
<gadget id="calculator">4 / 1</gadget>
<output>4</output>

<gadget id="calculator">4 / 10</gadget>
<output>2/5 = around 0.4</output>

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