Xiaolin is 15 years old this year. He asked the teacher how old he is this year. The teacher said: "When you are my age, I will be 47 years old." Please do the math, how old is the teacher this year.
小林今年15岁，他问老师今年多少岁，老师说："你到我这么大时，我已经47岁了．"请你算一算，老师今年多少岁．
<gadget id="calculator">47 - 15</gadget>
<output>32</output>

<gadget id="calculator">32 / 2</gadget>
<output>16</output>

<gadget id="calculator">15 + 16</gadget>
<output>31</output>

<result>31</result>