In the entrance examination for the Municipal Olympiad School last year, there were 40 students in a test room taking the test, and the average score of the top 10 students was 9 points higher than the average score of all the students in this test room, then the average score of the remaining 30 students was How much lower than the average score of all the students in this examination room.
在去年市奥校入学考试中，某个考室有40名同学参加考试，其中前10名同学的平均分比这个考室全部同学的平均分高9分，那么其余30名同学的平均分则比这个考室全部同学的平均分低多少分．
<gadget id="calculator">40 - 10</gadget>
<output>30</output>

<gadget id="calculator">9 / 30</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">10 * (3/10)</gadget>
<output>3</output>

<result>3</result>