Correct Answer - A
consider the following events :
E=Student A solves the problem
F=Student B solves the problem
G=Student C solves the problem
Clearly, E, F, G are independent events such that
P
(
E
)
=
1
2
,
P
(
F
)
=
1
3
and
P
(
G
)
=
1
4
P
Required probability
=
P
(
E
∪
F
∪
G
)
=
⇒
⇒
Required probability
=
1
−
P
(
¯¯¯
E
)
P
(
¯¯¯
F
)
P
(
¯¯¯
G
)
=
⇒
⇒
Required probability
=
1
−
1
2
×
2
3
×
3
4
=
3
4
=