There are 120 male and female teachers in the school, and the number of female teachers is three times that of male teachers. How many female teachers are there in the school?
学校有男教师和女教师共120人，其中女教师人数是男教师的3倍，学校有女教师多少人？
<gadget id="calculator">3 + 1</gadget>
<output>4</output>

<gadget id="calculator">120 / 4</gadget>
<output>30</output>

<gadget id="calculator">30 * 3</gadget>
<output>90</output>

<result>90</result>