Friday 13th
Logic
Level
2
What is the maximum number of times that "Friday the 13th" can occur in a single year (from January to December)?
1
2
3
4
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1 solution
We need to consider the case when there is a leap year and when there isn't a leap year. Here are two years, 2018 and 2020 (2020 being the leap year) and which day the 13th falls on:
2018:
2020:
We don't care what the name of the day that the 13th falls on is in these particular years, just which day of the week has the most repetition (since the days will all be shifted by the same amount in different years), and we see that it doesn't matter about a leap year, the answer will be 3 . If you want an example, 2015 was a 365 day year (when the year started on a Thursday), or 2012 was a 366 day year (when the year started on a Sunday).