Class 61 originally planned to select (1/4) students to do the general cleaning, but later 4 people volunteered to participate, so the number of people who participated in the general cleaning did not participate (1/2). How many people are there in this class?
六1班原来计划抽(1/4)的学生搞大扫除，但后来又有4人主动要求参加，这样参加大扫除的人数是未参加的(1/2)．这个班共有多少人？
<gadget id="calculator">1 + 2</gadget>
<output>3</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/3) - (1/4)</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">4 / (1/12)</gadget>
<output>48</output>

<result>48</result>