The 12th of September of a year falls on the same day of the week as the 12th of which month of the same year?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → December
The same date of a later month falls on the same day of the week when the days from the first date to the second make up 0 odd days (whole weeks). A month of 31 days has 3 odd days and a month of 30 days 2 odd days; February does not come in between, so the answer is the same in every year.
12 September to 12 October: September has 30 days, 2 odd days
12 October to 12 November: October has 31 days, 3 odd days (total 5)
12 November to 12 December: November has 30 days, 2 odd days (total 7)
7 odd days make one whole week, so 12th December falls on the same day as 12th September
Why the other options are incorrect
Option (1) October — Incorrect. September adds only 2 odd days, so 12th October is 2 days later in the week.
Option (3) November — Incorrect. September and October give \(2+3=5\) odd days, so 12th November is 5 days later in the week.
Option (4) August — Incorrect. August has 31 days, 3 odd days, so 12th September is 3 days later in the week than 12th August.