**FRIDAY
13**

**BY NIKKI
BACON **

**PROBLEM:
FRIDAY 13**

**1.
PROVE**
that there is at least one Friday the 13th in some month during each year.

**2.
PROVE **that
there is at most three Friday the 13ths any given year.

To prove that there is at least one Friday the 13th and at most 3 Friday the 13ths in any given year I used a spread sheet in excel. I set up a spread sheet to look at when and how many Friday the 13ths there were in a year when January 1st is either a Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, or Saturday. To see this spread sheet, click here. I did this for a leap year and a non leap year. By doing this, I exhausted all the possible Friday the 13ths in any given year.

I then went through the spread sheet and highlighted all the Friday the 13ths in every possible year. After highlighting, I organized my findings using excel. I found that there is at least one Friday the 13th in some month during each year and at most 3 Friday the 13ths in any given year. To see this, click here.

**3.
**Joe
Hooten, Professor Emeritus at the University of Georgia, observed in 1998
both February and March have a Friday the 13th. That is, there is a Friday
the 13th in two consecutive months.

**In what year will this occur again?**

**Is
there a cycle that can be specified for determining the years in which there
will be two consecutive months with Friday the 13th?**