Question

What is the probability of 53 Fridays in an ordinary year?

Answer 1

To determine the probability of having 53 Fridays in an ordinary year, we need to consider the possible combinations of days of the week for each month and take into account leap years.
In an ordinary year, there are 365 days. This means that there will be 52 complete weeks of 7 days each, which gives us 364 days. The remaining day can fall on any day of the week.
Since 7 does not divide evenly into 365, there will be one day left over. Therefore, there are two possibilities: either there will be 52 Fridays (with the remaining day falling on a different day of the week), or there will be 53 Fridays (with the remaining day falling on a Friday).
Hence, the probability of having 53 Fridays in an ordinary year is 1/7, or approximately 0.1429 (14.29%).