In a class of 87 students 41 are taking French, 22 are taking German. Of the students taking French or German, 9 are taking both courses. How many students are not enrolled in either course?	Select the correct option.
A) 6  B) 15  C) 24  D) 33  E) 54
Formula for calculating two overlapping sets:   A + B - both + NOT(A or B) = Total   so in our task we have equation:   41 (french) + 22 (german) - 9 (both) + NOT = 87   54 + NOT = 87   NOT = 87 - 54= 
<gadget id="calculator">87 - 54</gadget>
<output>33</output>
33   So answer is 33
<result>D</result>
In a class of 87 students 41 are taking French, 22 are taking German. Of the students taking French or German, 9 are taking both courses. How many students are not enrolled in either course?