There are three classes in the sixth grade, the number of the first class accounts for the whole grade (15/33), and the number of the third class is more than that of the second class (1/4). If the third shift transfers 4 people, it will be the same number as the second shift. How many students are there in the sixth grade?
六年级三个班，一班人数占全年级人数的(15/33)，三班人数比二班多(1/4)．如果三班调走4人，和二班人数同样多．六年级共有学生多少人？
<gadget id="calculator">15 / 33</gadget>
<output>5/11 = around 0.454545</output>

<gadget id="calculator">1 - (5/11)</gadget>
<output>6/11 = around 0.545455</output>

<gadget id="calculator">4 + 5</gadget>
<output>9</output>

<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">(6/11) * (5/9)</gadget>
<output>10/33 = around 0.30303</output>

<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">(6/11) * (4/9)</gadget>
<output>8/33 = around 0.242424</output>

<gadget id="calculator">(10/33) - (8/33)</gadget>
<output>2/33 = around 0.060606</output>

<gadget id="calculator">4 / (2/33)</gadget>
<output>66</output>

<result>66</result>