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CUET · MATHS · PYQ PAPER 2023

The probability that A speaks the truth is \(\frac{4}{5}\). He throws a die and reports that it is a five. The probability that it is actually a five is:

  1. A \(\frac{4}{9}\)
  2. B \(\frac{1}{2}\)
  3. C \(\frac{2}{9}\)
  4. D \(\frac{5}{9}\)
Verified Solution

Answer & Solution

Correct Answer

(A) \(\frac{4}{9}\)

Step-by-step Solution

Detailed explanation

\(P(\text{truth}) = \frac{4}{5}\) \(P(\text{lie}) = 1 - \frac{4}{5} = \frac{1}{5}\) \(P(\text{die is five}) = \frac{1}{6}\) \(P(\text{die is not five}) = \frac{5}{6}\) \(P(\text{reports five | die is five}) = P(\text{truth}) = \frac{4}{5}\)…