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TS EAMCET · Maths · Probability

If \(E_1, E_2 \ldots, E_n\) are an independent events such that \(P\left(E_r\right)=\frac{1}{1+r},(r=1,2, \ldots, n)\), then the probability that atleast one of \(E_1, E_2, \ldots, E_n\) happens is

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

Answer & Solution

Correct Answer

(C) \(\frac{n}{n+1}\)

Step-by-step Solution

Detailed explanation

We have, \(P\left(E_r\right)=\frac{1}{1+r}\) \(\therefore P\left(\bar{E}_r\right)=1-P\left(E_r\right)=1-\frac{1}{1+r}=\frac{r}{1+r}\) \(\therefore\) Required probability \(=P\left(E_1 \cup E_2 \cup E_3 \ldots \cup E_n\right)\)…