A survey of 126 Germanna students found that:
Formally

•92 students are taking at least an English class
•90 students are taking at least a Math class
•68 students are taking at least a Science class
•36 students are taking English, Math, and Science classes
•68 students are taking at least English and Math classes
•47 students are taking at least Math and Science classes
•51 students are taking at least English and Science classes

Symbolically
n(E)=92
n(M)=90
n(S)=68
n(ENMNS)=36
n(ENM)=68
n(MNS)=47
n(ENS)=51

Consider the following questions:

How many students are only taking an English class?

How many are taking only Math and Science classes?

How many students are not taking English, Math, or Science classes?​