When Xiaohui counted the average score of the final exam of this group, she found that if she got 15 points more, the group's average score would reach 92 points; if her own score was 5 points less, the group's average score would only be 90 points; How many people are there in their group?
小慧在统计本组期末考试平均成绩时发现：如果自己多得15分，小组的平均成绩就达到92分；如果自己的成绩少得5分，小组的平均成绩就只有90分；那么小慧他们小组有多少人．
<gadget id="calculator">15 + 5</gadget>
<output>20</output>

<gadget id="calculator">92 - 90</gadget>
<output>2</output>

<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<result>10</result>