If n{A} = 6, n{B} = 5 and n{A ∩ B} = 2, find n{A ∪ B}
A
7
B
8
C
9
D
13
E
15
Verified Correct Answer: C.
Step-by-Step Mathematical Solution
n(A U B) = n(A) + n(B) - n(A n B)
n(A U B) = 6 + 5 - 2 = 9
Source: Myschool Past Questions Archive (Record #41811)