The mother is 40 years old, and the daughter is 14 years old. When the daughter is old, the age of the mother is three times that of the daughter.
妈妈今年40岁，女儿14岁，女儿多少岁时，妈妈的年龄是女儿的3倍．
<gadget id="calculator">40 - 14</gadget>
<output>26</output>

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

<gadget id="calculator">26 / 2</gadget>
<output>13</output>

<result>13</result>