I'm beginning to study probability and an exercise in the study guide that asks me to calculate: What is the probability that the month January, of one year randomly selected have only four Sundays?
the solution of the book indicates that it's 4 / 7 which is equal to 0.5714 probability that the event occurs, according to what I learned in class the probability of this event can be calculated by counting probability as it is possible to have all elements of the sample space, and all the elements that belong to threw the probability of which is to be calculated.
P (A) = number of cases occurring A / number of cases in the sample space
My question is why the sample space of this experiment is 7 and what is the maximum number of Sundays in January that may have (I think by intuition that can be 5)
This formula applies when it is possible to have all elements of the sample space, and all items pertaining to the event whose probability is to be calculated