There are a total of 157 students in the three classes, and the number of boys in the three classes is equal. The boys in the first class account for (7/13) of the whole class, and the boys in the second class account for (4/7). Then the third class How many girls are in the class?
三个班学生共157人，且三个班男生人数相等，第一班男生占全班人数的(7/13)，第二班男生占全班人数的(4/7)，那么第三个班的女生人数是多少人？
<gadget id="calculator">157 - 52 - 49</gadget>
<output>56</output>

<gadget id="calculator">7 / 13</gadget>
<output>7/13 = around 0.538462</output>

<gadget id="calculator">52 * (7/13)</gadget>
<output>28</output>

<gadget id="calculator">56 - 28</gadget>
<output>28</output>

<result>28</result>