Paragraph: There are $n$ urns each containing $(n+1)$ balls such that the ith urn contains $i$ white balls and $(n+1-i)$ red balls. Let $u_i$ be the event of selecting ith urn, $i=1,2,3, \ldots, n$ and $W$ denotes the event of getting a white balls.Question: If $P\left(u_i\right)=c$, where $c$ is a constant, then $P\left(u_i / W\right)$ is equal to

• Correct answer
  A

  $\frac{2}{n+1}$
• B

  $\frac{1}{n+1}$
• C

  $\frac{n}{n+1}$
• D

  $\frac{1}{2}$

Hence, the correct answer is option: 'A'.