Xiaofang's father is 27 years older than Xiaofang. When Xiaofang's father is 2.5 times Xiaofang's age, how old is Xiaofang?
小芳的爸爸比小芳大27岁，当小芳爸爸的年龄是小芳年龄的2.5倍时，小芳多少岁．
<gadget id="calculator">2.5 - 1</gadget>
<output>1.5</output>

<gadget id="calculator">27 / 1.5</gadget>
<output>18</output>

<result>18</result>