The number of people who participated in the sports group in a certain class last semester accounted for 58% of the whole class, and 21 students did not participate. The number of people participating in the physical activity group this semester is 17 more than that of the previous semester. How many students in this class participate in the physical activity group this semester?
某班上学期参加体育活动小组的人数占全班人数的58%，有21个同学未参加．本学期参加体育活动小组的人数比上学期多17人，问本学期该班有多少学生参加体育活动小组？
<gadget id="calculator">58 / 100</gadget>
<output>29/50 = around 0.58</output>

<gadget id="calculator">1 - (29/50)</gadget>
<output>21/50 = around 0.42</output>

<gadget id="calculator">21 / (21/50)</gadget>
<output>50</output>

<gadget id="calculator">50 + 17</gadget>
<output>67</output>

<result>67</result>