The school organizes an extracurricular activity. The number of absentees is 10% of the attendance. Later, 2 people ask for leave due to illness. At this time, the ratio of absentees to attendance is 1:8. How many people are there in this school extracurricular activity group?
学校组织一次课外活动，缺勤人数是出勤人数的10%，后来又有2人因病请假，这时缺勤人数与出勤人数的比是1：8，这个学校课外活动小组共有多少人？
<gadget id="calculator">1 + 8</gadget>
<output>9</output>

<gadget id="calculator">1 / 9</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">1 + 10</gadget>
<output>11</output>

<gadget id="calculator">1 / 11</gadget>
<output>1/11 = around 0.090909</output>

<gadget id="calculator">(1/9) - (1/11)</gadget>
<output>2/99 = around 0.020202</output>

<gadget id="calculator">2 / (2/99)</gadget>
<output>99</output>

<result>99</result>