The ratio of the number of boys to the number of girls in a class is 4:5. If there are 24 boys, how many girls are there?
某班男生人数与女生人数的比是4：5，已知男生有24人，则女生有多少人．
<gadget id="calculator">24 / 4</gadget>
<output>6</output>

<gadget id="calculator">6 * 5</gadget>
<output>30</output>

<result>30</result>