Question 73

Mathematics Probability Hard

Consider the diagram given below and the following two statements:

Statement I: Regions \( \mathrm{X}, \mathrm{Y} \) and Z can be expressed as \( \mathrm{A} \cap \overline{\mathrm{B}}, \mathrm{A} \cap \mathrm{B} \) and \( \overline{\mathrm{A}} \cap \mathrm{B} \) respectively.
Statement II: \( \mathrm{P}(\mathrm{Y})=\mathrm{P}(\mathrm{A})-\mathrm{P}(\mathrm{X})=\mathrm{P}(\mathrm{B})-\mathrm{P}(\mathrm{Z}) \) .

In the light of the above statements, choose the most appropriate answer from the options given below:

Question Image
(A) Both Statement I and Statement II are true
(B) Both Statement I and Statement II are false
(C) Statement I is true but Statement II is false
(D) Statement I is false Statement II are true
View Dynamic Solution & Explanation
Correct Solution: Option A

Step-by-step Solution:

Statement I: Expressing Regions \(X, Y, Z\) in Set Notation From the given Venn diagram: - \( X \) is the part of \( A \) that is not in \( B \), i.e., \[ X = A \cap \bar{B} \] - \( Y \) is the part of both \( A \) and \( B \), i.e., \[ Y = A \cap B \] - \( Z \) is the part of \( B \) that is not in \( A \), i.e., \[ Z = \bar{A} \cap B \] Thus, Statement I is true. Statement II: Probability Expressions Using set notation and probability properties: - The total probability of \( A \) is the sum of the probabilities of regions \( X \) and \( Y \), i.e., \[ P(A) = P(X) + P(Y) \] Rearranging: \[ P(Y) = P(A) - P(X) \] - Similarly, the total probability of \( B \) is the sum of the probabilities of regions \( Y \) and \( Z \), i.e., \[ P(B) = P(Y) + P(Z) \] Rearranging: \[ P(Y) = P(B) - P(Z) \] Thus, the given probability equations are correct, and Statement II is true. Final Answer: Since both Statement I and Statement II are true, the correct option is: \[ \boxed{\text{A. Both Statement I and Statement II are true.}} \]