Question

8. If n(A) = 38, n(B) = 20 and n(
a intersection b) = 12, then find
(i) n(AUB)
​

Answer 1

To Find :-

we need to find the Value of n(A U B)

n(B - A)

n(A - B)

Given :

n(A) = 38

n(B) = 20

n(A ∩ B) = 12

By using Formula :-

◼ n( A U B ) + n(A ∩ B) = n(A) + n(B)

⇛n(A U B) + 12 = 38 + 20

⇛n(A U B) = 58 - 12

⇛n(A U B) = 46

Now,

n(A - B)

⇛ n(A - B) = n(A) - n(A ∩ B)

⇛ n(A - B) = 38 - 12

⇛ n(A - B) = 26

Now,

n(B - A)

⇛ n(B - A) = n(B) - n(A ∩ B)

⇛ n(B - A) = 20 - 12

⇛ n(B - A) = 8

Hence,

n(A U B) = 46

n(A - B) = 26

n(B - A) = 8