The calendar for the year 2009 will be same as that of the year –
2022
The calendar for the year 2009 will be same as that of the year –
- A.
2013
- B.
2015
- C.
2017
- D.
2019
Attempted by 82 students.
Show answer & explanation
Correct answer: B
Answer: 2015
Two years have identical calendars if they are both leap years or both common years and January 1 falls on the same weekday.
Compute the weekday shift from 2009 to a candidate year as: number of years difference + number of leap years between. If the total shift is a multiple of 7, the calendars match.
2013: difference = 4 years; leap years between = 2012 (1); shift = 4 + 1 = 5 -> not 0 mod 7, so calendars differ.
2015: difference = 6 years; leap years between = 2012 (1); shift = 6 + 1 = 7 -> 0 mod 7, and both are common years, so calendars match.
2017: difference = 8 years; leap years between = 2012, 2016 (2); shift = 8 + 2 = 10 -> 3 mod 7, so calendars differ.
2019: difference = 10 years; leap years between = 2012, 2016 (2); shift = 10 + 2 = 12 -> 5 mod 7, so calendars differ.
Therefore, the calendar for 2009 is the same as 2015.