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CUET · MATHS · PYQ PAPER 2023

The probability that a student is not a swimmer is \(\frac{1}{5}\). Then, the probability that out of 5 students, 4 are swimmers is

  1. A \({ }^5 C_4\left(\frac{1}{5}\right)\left(\frac{4}{5}\right)^4\)
  2. B \({ }^5 C_4\left(\frac{1}{5}\right)^4\left(\frac{4}{5}\right)\)
  3. C \({ }^5 C_3\left(\frac{1}{5}\right)^2\left(\frac{4}{5}\right)^3\)
  4. D \(\left(\frac{4}{5}\right)^4\left(\frac{1}{5}\right)\)
Verified Solution

Answer & Solution

Correct Answer

(A) \({ }^5 C_4\left(\frac{1}{5}\right)\left(\frac{4}{5}\right)^4\)

Step-by-step Solution

Detailed explanation

\( P(\text{swimmer}) = 1 - P(\text{not swimmer}) = 1 - \frac{1}{5} = \frac{4}{5} \) \( P(X=k) = { }^n C_k \, p^k \, (1-p)^{n-k} \)…