Prove that the calendar for the year 2003 will serve for the year 2014.
Answer
Answer (as printed):
Explanation
We must have same day on 1.1.2003 and 1.1.2014. So, number of odd days between 31.12.2002 and 31.12.2013 must be 0. This period has 3 leap years and 8 ordinary years. Number of odd days = (3 × 2 + 8 × 1) = 14 ≡ 0 odd day. ∴ Calendar for the year 2003 will serve for the year 2014.
Explanation as extracted from the printed page; notation may be imperfect.