There are 120 students in a certain grade participating in a mathematics competition, including 70 male students. Their average score is 1.5 points higher than the average score of all students. Ask how much lower the average score of female students is than the average score of all students.
某年级有120名同学参加数学竞赛，其中男同学有70人，他们的平均分比所有同学的平均分多1.5分，问女同学的平均分比所有同学的平均分低多少分．
<gadget id="calculator">120 - 70</gadget>
<output>50</output>

<gadget id="calculator">70 / 50</gadget>
<output>7/5 = around 1.4</output>

<gadget id="calculator">1.5 * (7/5)</gadget>
<output>2.1</output>

<result>2.1</result>