5. in a class of 78 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?
a. 6
b. 15
c. 24
d. 33
e. 54

B:15 Students
This is because 41 students (French) + 22 students (German) = 63 students
Of those 63, 9 are taking both French and German but they are already included in the counts of 41 and 22.
Since we know the languages of 63, we subtract 63 from 78 to find those who are taking neither. 
78-63=15