Question

14. If n(A - B) = 12, n(B - A) = 16 and n(A n B) = 5, find :
(i) n(A)
(ii) n(B)
(iii) n(AUB)​

Answer 1

Step-by-step explanation:

(i) n(A) = 12+5 = 17

(ii) n(B) = 16+5 = 21

(iii) n(AUB) = n(A) + n(B) - n(A n B)

=17 + 21 - 5

=33

Answer 2

(i) n(A)

We know that, n(A)=n(A−B)+n(A∩B)

=12+5

=17

(ii) n(B)

We know that, n(B)=n(B−A)+n(A∩B)

n(B)

=16+5

=21

(iii) n(A∪B)

We know that, n(A∪B)=n(A)+n(B)−n(A∩B)

=17+21−5

=38−5

n(A∪B)=33