Correct Answer - C
A leap year consists of 366 days comprising of 52 weeks and 2 days. There are 7 possibilities for these 2 extra days viz., (i) Sunday, Monday (ii) Monday, Tuesday (iii) Tuesday, Wednesday (iv) Wednesday, Thursday (v) Thursday, Friday (vi) Friday, Saturday (vii) Saturday, Sunday.
Let us consider two events :
A : The leap year contains 53 Sundays
B : The leap year contains 53 Mondays.
We have,
P(A)=
2
7
,P(B)=
2
7
,P(A∩B)=
1
7
Required probability
=P(A∪B)
=P(A)+P(B)-P(A∩B)=
2
7
+
2
7
-
1
7
=
3
7
