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If X and Y are two events such that PX//...

If X and Y are two events such that `PX//Y)=(1)/(2), P(Y//X)=(1)/(3)` and `P(XcapY)(1)/(6)`. Then, which of the following is/are correct ?

A

`P(XcupY)=2//3`

B

X and Y are independent

C

X and Y are not independent

D

`P(X^(c )capY)=1//3`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to use the given probabilities and the relationships between them. Let's denote the probabilities as follows: - \( P(X|Y) = \frac{1}{2} \) - \( P(Y|X) = \frac{1}{3} \) - \( P(X \cap Y) = \frac{1}{6} \) ### Step 1: Use the definition of conditional probability The conditional probability \( P(X|Y) \) is defined as: \[ P(X|Y) = \frac{P(X \cap Y)}{P(Y)} \] Substituting the known values: \[ \frac{1}{2} = \frac{\frac{1}{6}}{P(Y)} \] ### Step 2: Solve for \( P(Y) \) To find \( P(Y) \), we can rearrange the equation: \[ P(Y) = \frac{1}{6} \cdot 2 = \frac{1}{3} \] ### Step 3: Use the definition of the other conditional probability Now, we use the definition of \( P(Y|X) \): \[ P(Y|X) = \frac{P(X \cap Y)}{P(X)} \] Substituting the known values: \[ \frac{1}{3} = \frac{\frac{1}{6}}{P(X)} \] ### Step 4: Solve for \( P(X) \) Rearranging gives us: \[ P(X) = \frac{1}{6} \cdot 3 = \frac{1}{2} \] ### Step 5: Verify the values Now we have: - \( P(X) = \frac{1}{2} \) - \( P(Y) = \frac{1}{3} \) - \( P(X \cap Y) = \frac{1}{6} \) ### Step 6: Check the relationships We can check if the calculated probabilities satisfy the conditional probabilities: 1. **For \( P(X|Y) \)**: \[ P(X|Y) = \frac{P(X \cap Y)}{P(Y)} = \frac{\frac{1}{6}}{\frac{1}{3}} = \frac{1}{2} \quad \text{(Correct)} \] 2. **For \( P(Y|X) \)**: \[ P(Y|X) = \frac{P(X \cap Y)}{P(X)} = \frac{\frac{1}{6}}{\frac{1}{2}} = \frac{1}{3} \quad \text{(Correct)} \] ### Conclusion The calculated probabilities are consistent with the given conditional probabilities. Therefore, the values of \( P(X) \) and \( P(Y) \) are correct.

To solve the problem, we need to use the given probabilities and the relationships between them. Let's denote the probabilities as follows: - \( P(X|Y) = \frac{1}{2} \) - \( P(Y|X) = \frac{1}{3} \) - \( P(X \cap Y) = \frac{1}{6} \) ### Step 1: Use the definition of conditional probability ...
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