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NDA Mathematics Probability 2025 NDA 2025 (Phase 1)

NDA Mathematics Question (2025) — Solution

Question

If P(A) = 1 3 , P(B) = 1 2 and P(A B) = 1 4 , then what is the value of P(B | A^c)?

Options

  1. A. 1 8
  2. B. 3 8
  3. C. 5 8
  4. D. 7 8

Answer

B. 3 8

Step-by-step solution

The conditional probability is given by: P(B | A^c) = P(B A^c) P(A^c) The probability of the complement of A is: P(A^c) = 1 - P(A) = 1 - 1 3 = 2 3 The probability of B A^c is: P(B A^c) = P(B) - P(A B) = 1 2 - 1 4 = 1 4 Substituting these values into the formula: P(B | A^c) = 1 4 2 3 = 3 8 Answer: 3 8

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