There are 30 boys in Class 1, and there are fewer girls than boys (2/5). How many girls are there?
六一班有男生30人，女生比男生少(2/5)，女生有多少人？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

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

<result>18</result>