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Consider the following statements : if...

Consider the following statements :
if A and B are independent events, then
1. A and `bar(B)` are independent.
2. `barA` and B are independent.
3. `barA` and `barB` are independent.
Which of the above statements is/are correct ?

A

3 only

B

1 and 2 only

C

1, 2 and 3

D

None of these

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The correct Answer is:
To determine which statements are correct regarding the independence of events A and B, we will analyze each statement one by one. ### Given Information: - A and B are independent events. ### Definitions: - Two events A and B are independent if: \[ P(A \cap B) = P(A) \cdot P(B) \] - The complement of an event A is denoted as \( \bar{A} \) and represents the event that A does not occur. ### Statement 1: A and \( \bar{B} \) are independent. To prove this, we need to show: \[ P(A \cap \bar{B}) = P(A) \cdot P(\bar{B}) \] Using the property of complements: \[ P(\bar{B}) = 1 - P(B) \] Now, we can express \( P(A \cap \bar{B}) \) as: \[ P(A \cap \bar{B}) = P(A) - P(A \cap B) \] Since A and B are independent, we can substitute: \[ P(A \cap B) = P(A) \cdot P(B) \] Thus, \[ P(A \cap \bar{B}) = P(A) - P(A) \cdot P(B) = P(A)(1 - P(B)) = P(A) \cdot P(\bar{B}) \] This shows that A and \( \bar{B} \) are independent. ### Statement 2: \( \bar{A} \) and B are independent. To prove this, we need to show: \[ P(\bar{A} \cap B) = P(\bar{A}) \cdot P(B) \] Using the property of complements: \[ P(\bar{A}) = 1 - P(A) \] Now, we can express \( P(\bar{A} \cap B) \) as: \[ P(\bar{A} \cap B) = P(B) - P(A \cap B) \] Again, using the independence of A and B, we substitute: \[ P(A \cap B) = P(A) \cdot P(B) \] Thus, \[ P(\bar{A} \cap B) = P(B) - P(A) \cdot P(B) = P(B)(1 - P(A)) = P(B) \cdot P(\bar{A}) \] This shows that \( \bar{A} \) and B are independent. ### Statement 3: \( \bar{A} \) and \( \bar{B} \) are independent. To prove this, we need to show: \[ P(\bar{A} \cap \bar{B}) = P(\bar{A}) \cdot P(\bar{B}) \] Using the property of complements: \[ P(\bar{A} \cap \bar{B}) = 1 - P(A \cup B) \] Using the formula for the union of two events: \[ P(A \cup B) = P(A) + P(B) - P(A \cap B) = P(A) + P(B) - P(A) \cdot P(B) \] Thus, \[ P(\bar{A} \cap \bar{B}) = 1 - (P(A) + P(B) - P(A) \cdot P(B)) = 1 - P(A) - P(B) + P(A) \cdot P(B) \] Now, substituting \( P(\bar{A}) \) and \( P(\bar{B}) \): \[ P(\bar{A}) = 1 - P(A) \quad \text{and} \quad P(\bar{B}) = 1 - P(B) \] Thus, \[ P(\bar{A}) \cdot P(\bar{B}) = (1 - P(A))(1 - P(B)) = 1 - P(A) - P(B) + P(A) \cdot P(B) \] This shows that \( \bar{A} \) and \( \bar{B} \) are independent. ### Conclusion: All three statements are correct. Therefore, the answer is: 1. Statement 1 is correct. 2. Statement 2 is correct. 3. Statement 3 is correct. ### Final Answer: All statements (1, 2, and 3) are correct. ---

To determine which statements are correct regarding the independence of events A and B, we will analyze each statement one by one. ### Given Information: - A and B are independent events. ### Definitions: - Two events A and B are independent if: \[ ...
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