Question

Let A and B be two events. Suppose that P(A) = 0.22 and P(B) =0.21.

(a) Find P (A or B), given that A and B are mutually exclusive.
(b) Find P (A or B), given that A and B are independent.

Answer 1

For part (a), P(A or B) = 0.43.

For part (b), P(A or B) = 0.3838

Step-by-step explanation:

For part (a), since A and B are mutually exclusive events, the probability of A or B occurring is equal to the sum of their individual probabilities.

So P(A or B) = P(A) + P(B)

= 0.22 + 0.21

= 0.43.

For part (b), if A and B are independent events, the probability of A or B occurring is equal to 1 minus the probability of neither A nor B occurring.

So P(A or B) = 1 - P(not A and not B)

= 1 - P(not A)P(not B)

= 1 - (1 - P(A))(1 - P(B))

= 1 - (0.78)(0.79)

= 0.3838