Question

Let A and B be two finite sets such that n(A)=20,n(B)=28 and n(AUB)=36,find n(A∩B)​

Answer 1

Answer:

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

36=20+28-n(AnB)

n(AnB)=12

Answer 2

n(A ∩ B) = 12

Given:

n(A) = 20

n(B) = 28

n(A U B) = 36

To Find:

n(A ∩ B)

Calculating:

To solve these type of questions we use the formula:

n(A ∩ B) = n(A) + n(B) - n(A ∪B)

Substituting all the values known to us into this formula we get:

= 20 + 28 - 36

= 48 - 36

= 12

Therefore, the value of n(A ∩ B) = 12.