There are 30 students in Class 1, the ratio of boys to girls is 2; 3, how many girls are there?
六1班有30人，男生与女生的比是2；3，女生有多少人．
<gadget id="calculator">2 + 3</gadget>
<output>5</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">30 * (3/5)</gadget>
<output>18</output>

<result>18</result>