Question

Of the students in a certain class, 10 had taken a course in A, 11 had taken a course in

B, and 14 had taken a course in C. If 3 students had taken a course in all of the A, B,

and C, and 20 students had taken a course in only one of A, B, and C, how many

students had taken a course in exactly two of A, B, and C?​

Answer 1

Answer:

course in A = 11

course in B = 14

course in C = 3