There are 240 people in the painting class of Renmin Primary School, 30 people less than three times the number of people in the chess class. How many people are there in the chess class?
人民小学绘画班有240人，比象棋班人数的3倍少30人，象棋班有多少人？
<gadget id="calculator">240 + 30</gadget>
<output>270</output>

<gadget id="calculator">270 / 3</gadget>
<output>90</output>

<result>90</result>