## Aptitude Calendar Concepts and Formulas## Points to remember:1. Problems on calendar mainly deal with finding the day of the week on a given date using the number of odd days. 2. 3. To find the number of odd days divide the given number of by seven. The remainder left represents the number of odd days.
Similarly, if the given number of days is 77, after dividing 77 by 7, the remainder left is 0. Hence, there are 0 odd days. 4. 5. ## Counting odd:
∴100 years = 76 ordinary years + 24 leap years = [(76*52) weeks + 76 odd days] + [(24*52) weeks + 48 odd days] = [(100*52) weeks + 124 odd days] = (5200 weeks + 17 weeks + 5 odd days) = (5217 weeks + 5 odd days) ∴A century or 100 years have 5 odd days. Similarly, in 200 years, there will be 10 (5+5) days, 7 days (1 week) + 3 odd days. So, 200 years have 3 odd days. In 300 years, there will be 15 days, 14 days (2 weeks) + 1 odd day. So, 300 years have 1 odd day. In 400 years, there will be 20 + 1(as 400 is a leap year) = 21 days, 21 days (3 weeks). So, 400 years have 0 odd days. A century divisible by 400 also has 0 odd days. ## Tables of odd :a.) Table showing the relation between the year and the number of odd ;
b.) Table showing the relation between the day of the week and the number of odd ;
## Notes:- The years which are divisible by 400 have 0 odd days, e.g. 400, 800, 1200, 1600, 2000, etc.
- Last day of a century cannot be Tuesday, Thursday or Saturday.
- April & July for all years and January and October for non-leap years have the same calendar.
- The calendars of two different years are same if they satisfy the following conditions;
a) The years must be of the same type, i.e. both must be either ordinary years or leap years. b) January 21 of both the years, must be the same day of the week.
Aptitude Calendar Test Paper 1 Aptitude Calendar Test Paper 2 Next TopicCalendar |