There are n urns each continuous (n+1) balls such that the ithurn contains 'I' white balls and (n+1-i) red balls. Let `u_(1)` be the event of selecting ith urn, i=1,2,3……..n and W denotes the event of getting a white balls.
If n is even and E dentes the event of choosing even numbered urn`[P(u_(i))=(1)/(n)]`, then the value of `P(W//E)` is

Options

A. `(n+2)/(2n+1)`
B. `(n+2)/(2(n+1))`
C. `(n)/(n+1)`
D. `(1)/(n+1)`

Answer

B

Explanation

`P(W)/(E)=(2+4+6+...)/((n(n+1))/(2))=(n+2)/(2(n+1))`