1985 AJHSME Problem 20
Problem
In a certain year, January had exactly four Tuesdays and four Saturdays. On what day did January fall that year?
Solution
January has 31 days. If January 1 was on Monday or Tuesday, then there would have been 5 Tuesdays in the month. Similarly, if January 1 was on a Friday or Saturday, then there would have been 5 Saturdays in the month. Therefore, the answer is