Correct Answer -
17
105
17
Let
E
1
=
E
event of getting an electrification contract,
and
E
2
E
= event of getting a plumbing contract.
Then,
P
(
E
1
)
=
2
5
,
P
(
not
E
2
)
=
4
7
⇒
P
(
E
2
)
=
(
1
−
4
7
)
=
3
7
.
P
And,
P
(
E
1
∪
E
2
)
=
P
(
E
1
or
E
2
)
=
2
3
.
P
∴
∴
required probability
=
P
(
E
1
∩
E
2
)
=
=
P
(
E
1
)
+
P
(
E
2
)
−
P
(
E
1
∪
E
2
)
.
=