Question

Let A and B be two sets such that n(A)=5, n(AUB)=9, n(A∩B)=2; find n(B) ​

Answer 1

Answer:

n(AUB)= 9 n(A) = 5 n (ANB) then n(B) = 6

Answer 2

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

9 = 5 +n(B) - 2

9 = n(B) +3

+3 taking to left side

9- 3= n(B)

6 = n(B)

therefore n(B) = 6

I hope this will help you