In the first semester of the sixth grade, the number of girls in our school accounted for (2/5) of the whole class. In this semester, 4 girls were transferred. Now girls account for (3/7) of the whole class. How many students did our class have in the last semester? ?
我校六年级上学期女生人数占全班人数的(2/5)，这一学期又转来4个女生，现在女生占全班人数的(3/7)，我们班上学期有学生多少人？
<gadget id="calculator">7 - 3</gadget>
<output>4</output>

<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">5 - 2</gadget>
<output>3</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(3/4) - (2/3)</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">4 / (1/12) / (3/5)</gadget>
<output>80</output>

<result>80</result>