Question

There are 91 eighth-grade students signing up for electives.

Answer 1

Answer:

A). 81 students

B). 18 students

C). 10 students

Step-by-step explanation:

Let S = {All students of 8th grade} = 91

     A = {Students in Art} = 68

     B = {Students in band} = 31

Part A : A∪B = A + B - A∩B

            A∪B = 68 + 31 - 18

            A∪B = 81

A∪B represents the total number of students enrolled in art and band.

Part B : A∩B = 18

A∩B represents the number of common students enrolled in art and band.

Part C: ~(A∪B) = S - A∪B

           ~(A∪B) = 91 - 81

           ~(A∪B) = 10

~(A∪B) represents the number of students enrolled neither in art nor in band.