Someone asked a teacher how many students were in the class he taught. The teacher said: "Half the students are studying mathematics, 1/4 are studying music, 1/7 are studying foreign languages, and less than 6 students are studying in the pasture. Play football." Therefore, how many students are there in this class?
有人问一位老师，他教的班级有多少学生，老师说："一半学生在学数学，四分之一的学生在学音乐，七分之一的学生在念外语，还有不足6位学生正在草场踢足球．"因此，这个班一共有学生多少人．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

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

<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">1 - (1/2) - (1/4) - (1/7)</gadget>
<output>3/28 = around 0.107143</output>

<gadget id="calculator">3 / (3/28)</gadget>
<output>28</output>

<result>28</result>