What is the Probability of 52 Sundays in a Non-Leap Year?

getcalc.com's Probability calculator to find what is the probability of 52 Sundays in a non-leap year. The ratio of expected event to all the possible events of a sample space for 1 odd day not to be Sunday is the probability of getting 52 Sundays for a non-leap year.

P(A) = 6/7 = 0.86

Users may refer the below detailed information to learn how to find the probability of 52 Sundays in an ordinary year. The total number of weeks in a non-leap year {366 days = 52 (1/7)} is 52 weeks and one odd day. Since, finding the probability for an odd day not to be Sunday is enough to find the probability of getting 52 Sundays in an ordinary year of a Gregorian calendar by using any one of the below two methods.
Direct Method :
Workout
step 1 Possible outcomes for 1 odd day
The odd day may be either Sunday, Monday, Tuesday, Wednesday, Thursday, Friday or Saturday. Therefore, the total number of possible outcomes or elements of a sample space is 7.

step 2 Probability of 1 Odd day not to be Sunday
The sample space S = {Sun, Mon, Tue, Wed, Thu, Fri, Sat}
Expected events of A = {Mon, Tue, Wed, Thu, Fri, Sat}
P(A) = {Mon, Tue, Wed, Thu, Fri, Sat}/{Sun, Mon, Tue, Wed, Thu, Fri, Sat}
P(A) = 6/7
P(A) = 0.86

6/7 or 0.86 is probability for 52 Sundays in a non-leap year.


Complement Method :
Workout
step 1 Possible outcomes for 1 odd day
The odd day may be either Sunday, Monday, Tuesday, Wednesday, Thursday, Friday or Saturday. Therefore, the total number of possible outcomes or elements of a sample space is 7.

step 2 Probability of 1 Odd day to be Sunday
The sample space S = {Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday}
Expected event of A = {Sunday}

P(A) = {Sunday}/{Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday}
P(A) = 1/7
P(A) = 0.14

step 3 Finding the complement of event A for one odd day not to be Sunday
= 1 - P(A)
= 1 - 0.14
P(A’) = 0.86

0.86 is probability for 52 Sundays in a non-leap year.