There are 56 students in Class 3 and Class 4, and boys account for 3/7 of the total. How many girls are there in Class 3 and Class 4?
三4班共有56人，男生占总数的(3/7)，三4班女生有多少人．
<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">1 - (3/7)</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">56 * (4/7)</gadget>
<output>32</output>

<result>32</result>