If A and B are mutually exclusive events, then
A. P (A) ≤ P ()
B. P (A) ≥ P ()
C. P (A) < P ()
D. none of these
A & B are mutually exclusive events …… (given)
Thus, P (A ∩ B) = 0
Now, P (A U B) = P (A) + P (B) – P (A ∩ B) ……. (by general addition rule)
Thus, P (A U B) = P (A) + P (B) - P (A ∩ B)
P (A U B) = P (A) + P (B) – 0
P (A U B) = P (A) + P (B)
Now, for all events A, B
0 ≤P(A)≤1
Thus, P (A) + P (B) ≤ 1
P (A) ≤ 1 – P (B)
Thus, by complement rule,
P (A) ≤ P ()
Thus, option A is the correct answer.