Now the younger brother's age is half of the older brother's age. Three years ago, the younger brother's age was (1/3) of the older brother's age. How old is the younger brother this year?
现在弟弟年龄是哥哥年龄的一半，三年前弟弟年龄是哥哥的(1/3)，弟弟今年多少岁．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">3 * (1/3)</gadget>
<output>1</output>

<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">2 * (1/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 - (2/3)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">2 / (1/3)</gadget>
<output>6</output>

<result>6</result>