Aptitude - Calendar - Discussion

One other way of Finding the Answer is :

Just remember that 1st Jan 2000 was Saturday.

1999 (not leap year so 365 days) = 52 weeks + 1 day.
So to go to 1st Jan 1999 just have to subtract that 1 Extra day which is bringing the change.

In 100 years isn't this correct:

25 leap years + 75 ordinary years?

4*1=4 .. 4*2=8.. 4*3=12.. ......... 4*25=100 and so 25 leap years.

Sir, how you concluded 2 odd days from 121? Please explain me.

Anyone explain why 144025036146 is the codes for month explain how 1 arrives for January for ordinary year and 4 for feb again 4 for March I know 31/7=3 is code for feb leap year but why 144 for jan feb march.

How to calculate leap year in 100 years?

There's a better way to solve this:

We know that for 2000 years, the number of odd days is 0.
Consider 17 June, 2001.

for the previous 2000 years, there are 0 odd days.
for the year of 2001, starting from Jan
31+28+31+30+31+17 = 168

which means there are 0 odd days.

now the day of the week for 17 June 2001 is Sunday.

now we need the day for 17 June 1998. Simply subtract the odd days of the preceding three years.

2000 is a leap year, whereas 1999 and 1998 are ordinary years.

So 0 - 2 - 1 - 1 = -4.

Go back 4 days from Sunday and you get Wednesday.

Why it's needed to calculate odd days for 1600 and 300?

How to calculate ordinary year and leap years in one century?

Please explain?

Simple , leap year = 100 / 4 = 25.
Ordinary year = 100 - 25 = 75.

If you want to find number of odd days in 100 years, then 100/4=25.(Only. Quotient) Now,( 100 +25)/7=6(remainder).
So, there are 6 odd days in 100 no of Years.