There are 21 boys in class 6 and 2, and there are fewer girls than boys (1/7). How many people are there in the class?
六2班有男生21人，女生比男生少(1/7)，全班有多少人？
<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">1 - (1/7)</gadget>
<output>6/7 = around 0.857143</output>

<gadget id="calculator">21 * (6/7)</gadget>
<output>18</output>

<gadget id="calculator">18 + 21</gadget>
<output>39</output>

<result>39</result>