There are two classes A and B in the sixth grade of the school. The number of people in class A is that of class B (5/7). If 3 people are transferred from class B to class A, the number of people in class A will be that of class B (4/5). How many students are there in the sixth grade of the school?
学校六年级有甲、乙两个班，甲班人数是乙班的(5/7)．如果从乙班调3人到甲班，甲班人数就是乙班的(4/5)．学校六年级共有多少名学生？
<gadget id="calculator">5 + 4</gadget>
<output>9</output>

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

<gadget id="calculator">7 + 5</gadget>
<output>12</output>

<gadget id="calculator">5 / 12</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">(4/9) - (5/12)</gadget>
<output>1/36 = around 0.027778</output>

<gadget id="calculator">3 / (1/36)</gadget>
<output>108</output>

<result>108</result>