Question

If n(U) = 20 , n(A) = 12, n(B) = 11 and n(A U B)' =7 find n(A U B) ​

Answer 1

Answer:

n(U) = 20

n(A UB)' = 7

n(AUB)= n(U)-n(A U B)'

= 20-7 = 13

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

13 = 12 + 11 -x

x=23-13=10