Mom is 24 years older than Xiaohong. Seven years later, her mother will be three times as old as Xiaohong. How old is Xiaohong this year?
妈妈比小红大24岁，七年后妈妈的年龄是小红的三倍，小红今年多大？
<gadget id="calculator">3 - 1</gadget>
<output>2</output>

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

<gadget id="calculator">12 - 7</gadget>
<output>5</output>

<result>5</result>