3. There are 45 students in a class. The ratio of males to females is 3:2. How many fewer females than males?
三、一班共有45人，男、女生人数比为3：2，女生比男生少多少人？
<gadget id="calculator">3 + 2</gadget>
<output>5</output>

<gadget id="calculator">45 / 5</gadget>
<output>9</output>

<gadget id="calculator">3 * 9</gadget>
<output>27</output>

<gadget id="calculator">2 * 9</gadget>
<output>18</output>

<gadget id="calculator">27 - 18</gadget>
<output>9</output>

<result>9</result>