There are 40 students in a class of six years. In a math test, the average score of the top 15 students is 10 points higher than the average score of the whole class. How much is the average score of the rest of the students lower than the average score of the whole class?
六年一班有学生40人，一次数学考试，前15名的平均分比全班平均分高10分，其余同学的平均分比全班平均分低多少分？
<gadget id="calculator">10 * 15</gadget>
<output>150</output>

<gadget id="calculator">40 - 15</gadget>
<output>25</output>

<gadget id="calculator">150 / 25</gadget>
<output>6</output>

<result>6</result>