Let A and B be independent events. Denote P(A) as the probability that Event A will occur

Let A and B be independent events. Denote P(A) as the probability that Event A will occur, and denote P(A ∩ B) as the probability that Events A and B will both occur. Which of the following equations must be true?

1. P(A) = P(B)
2. P(A) = 1 - P(B)
3. P(A ∩ B) = P(A) + P(B)
4. P(A ∩ B) = P(A) · P(B)
5. P(A ∩ B) = P(A) + P(B) - (P(A) · P(B))

Answer

The correct answer is D.

You can calculate the chances of Events A and B both occurring by multiplying the probability of each event occurring.

That means that the correct expression is P(A ∩ B) = P(A) · P(B).