Events A and B are mutually exclusive. Also, P (A) = 0.25 and P (B) = 0.35. What is P (A or B) ?

A. 0.1

B. 0.25

C. 0.35

D. 0.6

The answer is D. 0.6

P (A or B) = P (A) + P (B) - P (A and B)

When the events are mutually exclusive, that means they cannot occur together:

P (A and B) is empty set, thus = 0

P (A) = 0.25

P (B) = 0.35

P (A or B) = 0.25 + 0.35 - 0 = 0.6