This year, Uncle Wang's age is equivalent to Teacher Jin's (4/7). After 12 years, Uncle Wang's age is exactly equivalent to Teacher Jin's (2/3). How old is Teacher Jin this year?
今年王叔叔的年龄相当于金老师的(4/7)，12年后，王叔叔的年龄又正好相当于金老师的(2/3)，今年金老师多少岁．
<gadget id="calculator">3 - 2</gadget>
<output>1</output>

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

<gadget id="calculator">7 - 4</gadget>
<output>3</output>

<gadget id="calculator">4 / 3</gadget>
<output>4/3 = around 1.333333</output>

<gadget id="calculator">2 - (4/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">12 / (2/3)</gadget>
<output>18</output>

<gadget id="calculator">4 / 7</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">(4/3) / (4/7)</gadget>
<output>7/3 = around 2.333333</output>

<gadget id="calculator">18 * (7/3)</gadget>
<output>42</output>

<result>42</result>