A and B are two mutually exclusive events is given
P (A) = 1/2 and P (B) = 1/3
We need to find P (A ‘or’ B).
P (A or B) = P (A ∪ B)
So by definition of mutually exclusive events we know,
P (A ∪ B) = P (A) + P (B)
= 1/2 + 1/3
= 5/6
∴ P (A ∪ B) is 5/6