Select 3 students on duty from 3 boys and 2 girls, and at least one of them must be a girl. How many different ways are there in total?
从3名男生、2名女生中选出3名值日生，其中至少要有1名女生，一共有多少种不同的选法？
<gadget id="calculator">3 * 2</gadget>
<output>6</output>

<gadget id="calculator">1 * 3</gadget>
<output>3</output>

<gadget id="calculator">6 + 3</gadget>
<output>9</output>

<result>9</result>