Correct Answer - C
Consider the following events :
A=Getting a white ball in first draw,
B=Getting a black ball in second draw.
Required probability =Probability of getting a white ball in first draw and a black ball in second draw
⇒
⇒
Required probability
=
P
(
A
∩
B
)
=
⇒
⇒
Required probability
=
(
P
(
A
)
P
(
B
/
A
)
=
Now,
P
(
A
)
=
.
10
C
1
.
25
C
1
=
10
25
=
2
5
P
and,
P
(
B
/
A
)
P
=Probability of getting a black ball in second draw when a white ball has already been in first draw
⇒
P
(
B
/
A
)
=
.
15
C
1
.
24
C
1
=
15
24
=
5
8
⇒
∴
∴
Required probability
=
2
5
×
5
8
=
1
4
=
.
