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A fair die is thrown twice. Let (a, b) d...

A fair die is thrown twice. Let (a, b) denote the outcome in which the first throw shows 'a' and the second throw shows 'b' . Let A and B be the following events :
A={(a,b): a is even}, B={(a,b): b is even}
Statement-1: If C={(a,b): a+b is odd}, then
`P(A cap B cap C)=(1)/(8)`
Statement-2: If D={(a,b): a+b is even}, then
`P(A cap B cap D// A cup B)=(1)/(3)`

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 step by step, we will analyze the two statements provided regarding the outcomes of throwing a fair die twice. ### Step 1: Define the Sample Space When a die is thrown twice, the sample space consists of all possible outcomes, which can be represented as pairs (a, b) where a is the result of the first throw and b is the result of the second throw. Since each die has 6 faces, the total number of outcomes is: \[ S = \{(1,1), (1,2), (1,3), (1,4), (1,5), (1,6), (2,1), (2,2), (2,3), (2,4), (2,5), (2,6), (3,1), (3,2), (3,3), (3,4), (3,5), (3,6), (4,1), (4,2), (4,3), (4,4), (4,5), (4,6), (5,1), (5,2), (5,3), (5,4), (5,5), (5,6), (6,1), (6,2), (6,3), (6,4), (6,5), (6,6)\} \] The total number of outcomes is \(6 \times 6 = 36\). ### Step 2: Define Events A, B, C, and D - **Event A**: The first throw (a) is even. Possible values for a are {2, 4, 6}. - **Event B**: The second throw (b) is even. Possible values for b are {2, 4, 6}. - **Event C**: The sum \(a + b\) is odd. This occurs when one of a or b is even and the other is odd. - **Event D**: The sum \(a + b\) is even. This occurs when both a and b are either even or both are odd. ### Step 3: Calculate Probabilities for Statement 1 **Statement 1**: \(P(A \cap B \cap C) = \frac{1}{8}\) - **Finding \(A \cap B\)**: - A consists of outcomes where a is even: {2, 4, 6}. - B consists of outcomes where b is even: {2, 4, 6}. - The intersection \(A \cap B\) consists of outcomes where both a and b are even: \[ A \cap B = \{(2,2), (2,4), (2,6), (4,2), (4,4), (4,6), (6,2), (6,4), (6,6)\} \] This gives us 9 outcomes. - **Finding \(C\)**: Since \(C\) requires \(a + b\) to be odd, and both a and b are even in \(A \cap B\), it is impossible for \(a + b\) to be odd. Therefore: \[ A \cap B \cap C = \emptyset \] Hence, \[ P(A \cap B \cap C) = 0 \] ### Conclusion for Statement 1 Since \(P(A \cap B \cap C) = 0\), Statement 1 is false. ### Step 4: Calculate Probabilities for Statement 2 **Statement 2**: \(P(A \cap B \cap D) / P(A \cup B) = \frac{1}{3}\) - **Finding \(D\)**: - \(D\) consists of outcomes where \(a + b\) is even. This includes outcomes where both a and b are even or both are odd. - **Finding \(A \cap B \cap D\)**: Since \(A \cap B\) consists of outcomes where both a and b are even, all of these outcomes will also satisfy \(D\). Thus: \[ A \cap B \cap D = A \cap B = 9 \text{ outcomes} \] - **Finding \(A \cup B\)**: - Outcomes where a is even or b is even can be calculated as: \[ A \cup B = \{(2,1), (2,2), (2,3), (2,4), (2,5), (2,6), (4,1), (4,2), (4,3), (4,4), (4,5), (4,6), (6,1), (6,2), (6,3), (6,4), (6,5), (6,6), (1,2), (3,2), (5,2), (1,4), (3,4), (5,4), (1,6), (3,6), (5,6)\} \] This gives us 27 outcomes. - **Calculating the Probability**: \[ P(A \cap B \cap D) = \frac{9}{36} = \frac{1}{4} \] \[ P(A \cup B) = \frac{27}{36} = \frac{3}{4} \] Thus, \[ \frac{P(A \cap B \cap D)}{P(A \cup B)} = \frac{\frac{1}{4}}{\frac{3}{4}} = \frac{1}{3} \] ### Conclusion for Statement 2 Since \(P(A \cap B \cap D) / P(A \cup B) = \frac{1}{3}\), Statement 2 is true. ### Final Answer - Statement 1 is false. - Statement 2 is true.

To solve the problem step by step, we will analyze the two statements provided regarding the outcomes of throwing a fair die twice. ### Step 1: Define the Sample Space When a die is thrown twice, the sample space consists of all possible outcomes, which can be represented as pairs (a, b) where a is the result of the first throw and b is the result of the second throw. Since each die has 6 faces, the total number of outcomes is: \[ S = \{(1,1), (1,2), (1,3), (1,4), (1,5), (1,6), (2,1), (2,2), (2,3), (2,4), (2,5), (2,6), (3,1), (3,2), (3,3), (3,4), (3,5), (3,6), (4,1), (4,2), (4,3), (4,4), (4,5), (4,6), (5,1), (5,2), (5,3), (5,4), (5,5), (5,6), (6,1), (6,2), (6,3), (6,4), (6,5), (6,6)\} \] The total number of outcomes is \(6 \times 6 = 36\). ...
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