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A lot contains equal number of defective...

A lot contains equal number of defective and non defective bulbs. Two bulbs ar drawn at random, one at a time, with replacement. The events A, B, C are defined as
A : The first bulb is defective
B : The second bulb is non defective
C : Two bulbs are either both defective and non defective.
Statement-1 : A, B, C are pairwise independent.
Statement-2 : A, B, C are mutually independent.

A

Statement-1 is true, Statement-2 is true, Statement-2 is a correct explanation for statement -1

B

Statement-1 is true, Statement-2 is true, Statement-2 is Not a correct explanation for statement -1

C

Statement-1 is true, Statement-2 is False

D

Statement-1 is False, Statement-2 is true

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to analyze the events A, B, and C defined in the question and determine their independence. ### Step-by-Step Solution: 1. **Define the Events:** - Let \( A \): The event that the first bulb drawn is defective. - Let \( B \): The event that the second bulb drawn is non-defective. - Let \( C \): The event that both bulbs are either both defective or both non-defective. 2. **Determine Probabilities:** - Since there are equal numbers of defective and non-defective bulbs, the probability of drawing a defective bulb (event \( A \)) is: \[ P(A) = \frac{1}{2} \] - Similarly, the probability of drawing a non-defective bulb (event \( B \)) is: \[ P(B) = \frac{1}{2} \] - For event \( C \), we need to calculate the probability of both bulbs being either both defective or both non-defective: - The probability of both bulbs being defective: \[ P(A \cap A) = P(A) \times P(A) = \frac{1}{2} \times \frac{1}{2} = \frac{1}{4} \] - The probability of both bulbs being non-defective: \[ P(B \cap B) = P(B) \times P(B) = \frac{1}{2} \times \frac{1}{2} = \frac{1}{4} \] - Therefore, the probability of event \( C \) is: \[ P(C) = P(A \cap A) + P(B \cap B) = \frac{1}{4} + \frac{1}{4} = \frac{1}{2} \] 3. **Check Pairwise Independence:** - For events to be pairwise independent, the following must hold true: - \( P(A \cap B) = P(A) \times P(B) \) - \( P(A \cap C) = P(A) \times P(C) \) - \( P(B \cap C) = P(B) \times P(C) \) - Calculate \( P(A \cap B) \): \[ P(A \cap B) = P(A) \times P(B) = \frac{1}{2} \times \frac{1}{2} = \frac{1}{4} \] - Calculate \( P(A \cap C) \): - \( C \) includes both defective and non-defective scenarios. Hence, \( P(A \cap C) \) is the probability of the first bulb being defective and both being the same: \[ P(A \cap C) = P(A \cap A) = \frac{1}{4} \] - Check: \[ P(A) \times P(C) = \frac{1}{2} \times \frac{1}{2} = \frac{1}{4} \] - Calculate \( P(B \cap C) \): - Similarly, \( P(B \cap C) \) is the probability of the first bulb being non-defective and both being the same: \[ P(B \cap C) = P(B \cap B) = \frac{1}{4} \] - Check: \[ P(B) \times P(C) = \frac{1}{2} \times \frac{1}{2} = \frac{1}{4} \] - Since all pairwise independence conditions are satisfied, events \( A, B, C \) are pairwise independent. 4. **Check Mutual Independence:** - For mutual independence, we need: \[ P(A \cap B \cap C) = P(A) \times P(B) \times P(C) \] - However, \( P(A \cap B \cap C) \) cannot be calculated directly as it requires specific combinations of the events. Since we have established that \( A \) and \( B \) can occur independently of \( C \) but not necessarily together, we find that they are not mutually independent. ### Conclusion: - **Statement 1**: True (A, B, C are pairwise independent). - **Statement 2**: False (A, B, C are not mutually independent).
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