If n(A U B)=22, n(A ∩ B)=8, and n(B)=12, find n(A)

Question

If n(A)=8, n(B)=14 and n(A ∩ B)=5, find n(A U B)

Answer 1

n(A U B) = n(A) + n(B) - n(A ∩ B)
22 = n(A) + 12 - 8
n(A) = 18

I figure you can get the other answer