Question

If n(A)=5; n(B) = 7 and A subset of B then n(AUB)​

Answer 1

Answer:Given A⊂B, n(A)=5 and n(B)=7

Since, A⊂B⇒ all the elements of set A are also present in set B ⇒n(A∩B)=5

Since, n(A∪B)=n(A)+n(B)−n(A∩B)

⇒n(A∪B)=5+7−5

⇒n(A∪B)=7

Step-by-step explanation:please mark me as brainlist and give me thnks.