The younger brother's age is now (1/2) the older brother's age, but 9 years ago the younger brother's age was only (1/5) the older brother's age. What is the older brother's age now?
现在弟弟的年龄是哥哥龄的(1/2)，而9年前弟弟年龄只是哥哥的(1/5)，哥哥现在的年龄是多少岁？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/5) * 9</gadget>
<output>9/5 = around 1.8</output>

<gadget id="calculator">9 - (9/5)</gadget>
<output>36/5 = around 7.2</output>

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

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(36/5) / (3/5)</gadget>
<output>12</output>

<gadget id="calculator">2 * 12</gadget>
<output>24</output>

<result>24</result>