Prove that there is at least one Friday the 13th in some month during each year.
Prove that there are at most three Friday the 13ths any given year.
Joe Hooten, Professor Emeritus at the University of Georgia, observed that 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?