If A and B are finite sets such that
Question:
If A and B are finite sets such that A ⊂ B, then n(A ∪ B) = ____________.
Solution:
Let n(A) = m
n(B) = n, since both are finite set
Since A⊂B then A∪B = B
⇒ n(A∪B) = n(B)
n(A∪B) = n = n(B)