- A
- B
- C
- D
View written solutionFree
Correct answer: C
Step-by-step Solution
1. Define the experimental setup and initial probabilities.
Let's denote the contents of the boxes and the probabilities of choosing a ball of a certain color from Box-I.
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Box-I: 8 Red (R1), 3 Blue (B1), 5 Green (G1). Total = 16 balls.
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Box-II (if R1 is chosen): 24 Red (R2), 9 Blue (B2), 15 Green (G2). Total = 48 balls.
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Box-III (if B1 is chosen): 1 Blue (B3), 12 Green (G3), 3 Yellow (Y3). Total = 16 balls.
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Box-IV (if G1 is chosen): 10 Green (G4), 16 Orange (O4), 6 White (W4). Total = 32 balls.
2. Define the events for conditional probability.
We need to find the conditional probability , where:
- = The event that 'one of the chosen balls is white'.
- = The event that 'at least one of the chosen balls is green'.
The formula for conditional probability is .
3. Calculate the probability of event F, .
Event ('at least one green ball') can happen in the following mutually exclusive ways:
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Case 1: The first ball from Box-I is green (). The second ball can be anything. The condition is already met.
- The probability of this case is .
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Case 2: The first ball is red () and the second ball is green ().
- .
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Case 3: The first ball is blue () and the second ball is green ().
- .
The total probability of event is the sum of the probabilities of these cases: To add these fractions, we find a common denominator, which is 64:
4. Calculate the probability of the intersection event, .
- Event ('one white ball') can only occur if the second ball is white. White balls are only in Box-IV. To choose from Box-IV, the first ball must be green ().
- So, event is the sequence of drawing a green ball from Box-I and then a white ball from Box-IV.
- Now consider the intersection event : 'one white ball' AND 'at least one green ball'.
- If event occurs, the first ball drawn is green (). This means the condition for event ('at least one green ball') is automatically satisfied.
- Therefore, event is a subset of event (), which implies that .
- So, .
5. Calculate the conditional probability .
Using the formula for conditional probability: Since , we can simplify: Now, we can simplify the fraction by dividing the numerator and denominator by 3:
Thus, the required conditional probability is .
Conclusion: Comparing the result with the given options, the correct option is C.
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