The age difference between father and son is 26 years old. The age ratio of father and son this year is 3:1. How old is father this year?
父子俩的年龄差是26岁，父子俩今年的年龄比是3：1，父亲今年多少岁．
<gadget id="calculator">3 - 1</gadget>
<output>2</output>

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

<gadget id="calculator">3 * 13</gadget>
<output>39</output>

<result>39</result>