Aptitude - Calendar - Discussion

Discussion Forum : Calendar - General Questions (Q.No. 4)
4.
What will be the day of the week 15th August, 2010?
Sunday
Monday
Tuesday
Friday
Answer: Option
Explanation:

15th August, 2010 = (2009 years + Period 1.1.2010 to 15.8.2010)

Odd days in 1600 years = 0

Odd days in 400 years = 0

9 years = (2 leap years + 7 ordinary years) = (2 x 2 + 7 x 1) = 11 odd days 4 odd days.

Jan.  Feb.   March    April    May  June  July  Aug. 
(31 +  28  +  31   +   30   +  31  + 30  + 31  + 15) = 227 days

227 days = (32 weeks + 3 days) 3 odd days.

Total number of odd days = (0 + 0 + 4 + 3) = 7 0 odd days.

Given day is Sunday.

Discussion:
95 comments Page 10 of 10.

Ayesha said:   1 decade ago
Please explain how to take 9 years = 2 leap years + 7 ordinary years.

Arjun said:   1 decade ago
Year Code Month Code Day Code

1600-1699=6 Jan-0 Sun-0
1700-1799=4 Feb-3 Mon-1
1800-1899=2 Mar-3 Tue-2
1900-1999=0 Apr-6 Wed-3
2000-2099=6 May-1 Thu-4
2100-2199=4 Jun-4 Fri-5
July-6 Sat-6
Aug-2
Sept-5
Oct-0
Nov-3
Dec-5

Note: Day+Year+Leap Year+Year Code+Month Code

First we need to calculate leap year; it is calculated on 2010 and we need to take last two digits i.e;(10).

2)10(5
10
----
0 leave 0 and take only quotient i.e;5

Now come to formula
D+Y+L.Y+Y.C+M.C ==> 15+10+5+0+2 = 32.

2)32(16
2
------
12
12
------
0

The 0 shows day's code.
.'.2010 Aug 15th is Sunday.

Note: While calculating leap year, take last two digits from the year.
And considering year in the problem we need to take last two digits (i.e;10 in the problem).

Thank You & Regards,
Arjun.

Nishant said:   1 decade ago
@Sunita.

97 year == Divide 97 by 4:
= Quotient is 24.
= So 24 is leap year and in 1 leap year has 2 odd days.
= Than (97-24= 73): 73 is ordinary year and 1 ordinary year has 1 odd day.
= 24*2 + 73*1= 121 days.
=121/7 = than reminder equal to 2.
= So 2 is odd days.

Sunita said:   1 decade ago
I am not able to understand that how you calculate ordinary and leap years in 100 years, 97 years.

Is there any formula for that?

Akhil said:   1 decade ago
@Gpvsai : 15+2+10+2+6 = 35.

So, dividing 35 by 7 we get 5 which is friday.


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