Add the same number to the numerator and denominator of the fraction (3/11) and get (3/5) after dividing. What is the added number?
分数(3/11)的分子分母加上同一个数，约分后得(3/5)，所加的这个数是多少．
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(3/5) * 11</gadget>
<output>33/5 = around 6.6</output>

<gadget id="calculator">(33/5) - 3</gadget>
<output>18/5 = around 3.6</output>

<gadget id="calculator">1 - (3/5)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(18/5) / (2/5)</gadget>
<output>9</output>

<result>9</result>