In the school chorus, there are 27 more boys than girls, and the number of boys is four times that of girls. How many girls are there in the chorus?
学校合唱队，男生比女生多27人，男生人数是女生的4倍．合唱队里女生有多少人？
<gadget id="calculator">4 - 1</gadget>
<output>3</output>

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

<result>9</result>