Teacher Zeng is 48 years old this year, and her three students are 10, 11 and 13 years old. How many years later the sum of the ages of the three students is equal to the age of Mr. Zeng.
曾老师今年48岁，她的3个学生的年龄分别是10岁、11岁和13岁．多少年后3个学生的年龄之和等于曾老师的年龄．
<gadget id="calculator">48 - 10 - 11 - 13</gadget>
<output>14</output>

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

<gadget id="calculator">14 / 2</gadget>
<output>7</output>

<result>7</result>