Question:
The probability that a non-leap year has 53 sundays, is
(a) $\frac{2}{7}$
(b) $\frac{5}{7}$
(C) $\frac{6}{7}$
(d) $\frac{1}{7}$
Solution:
GIVEN: A non leap year
TO FIND: Probability that a non leap year has 53 Sundays.
Total number of days in non leap year is 365days
Hence number of weeks in a non leap year is 
In a non leap year we have 52 complete weeks and 1 day which can be any day of the week e.g. Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, and Saturday
To make 53 Sundays the additional day should be Sunday
Hence total number of days is 7
Favorable day i.e. Sunday is 1
We know that PROBABILITY = 
Hence probability that a non leap year has 53 Sundays is
Hence the correct option is 