High School

The events A, B, and C are such:

* A and B are independent.
* B and C are independent.
* A and C are mutually exclusive.
* Their probabilities are P(A) = 0.3, P(B) = 0.4, and P(C) = 0.2.

Calculate the probability of the following events occurring:

10.1.1 Both A and C occur.
10.1.2 Both B and C occur.
10.1.3 At least ONE of A or B occurs.

Answer :

To solve this problem involving events A, B, and C, we need to understand how their probabilities interact based on the given conditions.

10.1.1 Both A and C occur:

Since A and C are mutually exclusive events, they cannot occur at the same time. Mutually exclusive means that if one event happens, the other cannot. Therefore, the probability of both A and C occurring is:

[tex]P(A \cap C) = 0[/tex]

10.1.2 Both B and C occur:

B and C are independent events. The probability that both B and C occur is found by multiplying their individual probabilities:

[tex]P(B \cap C) = P(B) \times P(C) = 0.4 \times 0.2 = 0.08[/tex]

10.1.3 At least ONE of A or B occurs:

To find the probability that at least one of A or B occurs, we use the formula for the probability of the union of two independent events:

[tex]P(A \cup B) = P(A) + P(B) - P(A \cap B)[/tex]

Since A and B are independent, the probability of both A and B occurring is:

[tex]P(A \cap B) = P(A) \times P(B) = 0.3 \times 0.4 = 0.12[/tex]

Now, substitute the values into the formula:

[tex]P(A \cup B) = 0.3 + 0.4 - 0.12 = 0.58[/tex]

Therefore, the probability of at least one of A or B occurring is 0.58.

In summary:

  1. The probability of both A and C occurring is 0.

  2. The probability of both B and C occurring is 0.08.

  3. The probability of at least one of A or B occurring is 0.58.