Correct Answer - A
We have, P(Ui)=C,i=1,2,3,..,n
∴
n
∑
i=1
P(Ui)=1⇒
n
∑
i=1
C=1⇒C=
1
n
∴P(Ui)=
1
n
,i=1,2,3,..,n
∴P(Un/W)=
P(Un∩W)
P(W)
⇒P(Un/W)=
P(Un∩W)
∑n
i=1
(Ui∩W)
⇒P(UnRW)=
P(Un)P(W/Un)
∑i=1nP(Ui)P(W/Ui)
=
1
n
×
n
n+1
∑n
i=1
C×
1
n+1
⇒P(Un/W)=
1
C
∑n
i=1
i
=
1
1
n
×
n(n+1)
2
=
2
n+1