The number of boys in class 31 is 12 more than the number of girls. If the number of boys decreases (1/2) and the number of girls decreases (1/5), then the number of boys and girls is equal. How many students are there in this class?
三1班男生人数比女生人数多12人，如果男生人数减少(1/2)，女生减少(1/5)，则男女生人数相等．这个班共有学生多少人？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (1/2)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(4/5) / (1/2)</gadget>
<output>8/5 = around 1.6</output>

<gadget id="calculator">1 / (8/5)</gadget>
<output>5/8 = around 0.625</output>

<gadget id="calculator">1 - (5/8)</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">12 / (3/8)</gadget>
<output>32</output>

<gadget id="calculator">32 - 12</gadget>
<output>20</output>

<gadget id="calculator">20 + 32</gadget>
<output>52</output>

<result>52</result>