The ratio of boys to girls in the sixth grade is 3:4, and now there are 6 more girls, and the ratio of boys to girls is 3:5. How many students were there in the sixth grade?
六年级男生和女生的比是3：4，现在又来了6名女生，这时男生和女生的比是3：5，问六年级原来有多少学生？
<gadget id="calculator">5 / 3</gadget>
<output>5/3 = around 1.666667</output>

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

<gadget id="calculator">(5/3) - (4/3)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">6 / (1/3)</gadget>
<output>18</output>

<gadget id="calculator">18 * (4/3)</gadget>
<output>24</output>

<gadget id="calculator">18 + 24</gadget>
<output>42</output>

<result>42</result>