The number of girls in the sixth grade class is 12 fewer than the whole class (4/7), and the ratio of the number of girls to the number of boys is 2:3. How many students are there in the sixth grade class?
六年级一班女生人数比全班人数的(4/7)少12人，女生人数与男生人数的比是2：3，六年级一班共有学生多少人？
<gadget id="calculator">4 / 7</gadget>
<output>4/7 = around 0.571429</output>

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

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

<gadget id="calculator">(4/7) - (2/5)</gadget>
<output>6/35 = around 0.171429</output>

<gadget id="calculator">12 / (6/35)</gadget>
<output>70</output>

<result>70</result>