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TS EAMCET · Maths · Probability

In a book of 500 pages, it is found that there are 250 typing errors. Assume that Poisson law holds for the number of errors per page. Then, the probability that a random sample of 2 pages will contain no error, is :

  1. A \(e^{-0.3}\)
  2. B \(e^{-0.5}\)
  3. C \(e^{-1}\)
  4. D \(e^{-2}\)
Verified Solution

Answer & Solution

Correct Answer

(C) \(e^{-1}\)

Step-by-step Solution

Detailed explanation

Here number of errors per page \(=\frac{250}{500}=\frac{1}{2}\) and \(\quad n=2\) \(\therefore \quad \lambda=n p=2 \times \frac{1}{2}=1\) and probability of no error \(P(X=0)=\frac{e^{-1} \times(1)^0}{0 !}=e^{-1}\)