There are 42 people in the school chorus group, which is 8 people less than 2.5 times that of the art group. How many people are there in the art group?
学校合唱小组有42人，比美术组的2.5倍少8人，美术小组有几人？
<gadget id="calculator">8 + 42</gadget>
<output>50</output>

<gadget id="calculator">50 / 2.5</gadget>
<output>20</output>

<result>20</result>