1st January 2004 was a Thursday. Which day of the week was 31st December of the same year?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Friday
The day moves forward by the odd days (days left over after whole weeks) between the two dates. 2004 is divisible by 4, so it is a leap year and February has 29 days.
1 January to 31 January: 30 days, 2 odd days
February 29 days 1, March 3, April 2, May 3, June 2, July 3, August 3, September 2, October 3, November 2, December 3
Total \(=2+1+3+2+3+2+3+3+2+3+2+3=29\)
\(29=4\times7+1\), so 1 odd day
Thursday + 1 day = Friday