Use the union rule to answer.
If n(A) = 10, n(B) = 15 and n(a ∩ B) = 9, what is n(A U B)?
Solution:-
The union rule for sets is symbolized n(A U B) = n(A) + n(B) – n(A ∩B). For this problem, you are given all the numbers necessary to apply the formula.
n(A) = 10
n(B) = 15
n(A ∩ B) = 9
Substitute each number into the formula.
n(A U B) = n(A) + n(B) – n(A ∩ B)
n(A U B) = 10 + 15 – 9
=16