

In a non leap year, there are 365 days i.e., 52 weeks and 1 day.
In 52 weeks, there are 52 Sundays.
Therefore, the probability that the non leap year will contain 53 Sundays is equal to the
probability that the remaining 1 day will be Sunday.
The remaining 1 days can be:
Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, and Sunday
So, total number of cases = 7
And favorable cases = 1
Hence, the probability that a non leap year will have 53 Sundays = 1/7
