Question : The last Sunday of March, 2006 fell on which date ? Statements : I.…
2025
Question : The last Sunday of March, 2006 fell on which date ?
Statements :
I. The first Sunday of that month fell on 5th.
II. The last day of that month was Friday.
- A.
I alone is sufficient while II alone is not sufficient
- B.
II alone is sufficient while I alone is not sufficient
- C.
Either I or II is sufficient
- D.
Neither I nor II is sufficient
Attempted by 7 students.
Show answer & explanation
Correct answer: C
Concept: In a calendar data-sufficiency problem, once any single date-to-weekday pairing in a month is known, every other occurrence of any weekday in that same month can be located by adding or subtracting multiples of 7 days. So a statement is 'sufficient' here if it anchors even one such pairing anywhere in the month -- it does not need to be the pairing asked about directly.
Application:
From Statement I: the first Sunday fell on the 5th. Adding 7 repeatedly gives Sundays on the 5th, 12th, 19th and 26th. Since March has 31 days, the 26th is the last Sunday of the month -- Statement I alone fixes the answer.
From Statement II: the last day of March (the 31st) was a Friday. Counting back day by day -- 30th Thursday, 29th Wednesday, 28th Tuesday, 27th Monday, 26th Sunday -- also identifies the 26th as the last Sunday -- Statement II alone, independently of Statement I, fixes the same answer.
Cross-check: Both routes -- counting forward from a known Sunday and counting backward from a known last-day weekday -- converge on the same date, the 26th. Since each statement independently pins down the answer without needing the other, the correct choice is that either statement alone is sufficient.