There are 32 boys and 18 girls in the kindergarten class and the middle class. It is known that the ratio of the number of boys to the number of girls in the big class is 5:3, and the ratio of the number of boys to the number of girls in the middle class is 2:1, so what is the number of girls in the big class?
幼儿园大班和中班共有32个男生，18个女生．已知大班中男生数与女生数的比为5：3，中班中男生数与女生数的比为2：1，那么大班的女生数等于多少．
<gadget id="calculator">3 * 2</gadget>
<output>6</output>

<gadget id="calculator">18 - 6</gadget>
<output>12</output>

<result>12</result>