2022_IAS_Qn A7. Which date of June 2099 among the following is Sunday?

Which date of June 2099 among the following is Sunday?

(a) 4
(b) 5
(c) 6
(d) 7

[AbdusCSATMATH]

To find an unknown date, need to know a reference date.
1st January 2001 is Monday.
From 2001 to 2098 there are 98 years. In these 98 years, 98/4=24 are leap years and the remaining 98-24=74 are non-leap years.
Then number of odd days in these 98 years duration = number of odd days in 24 LYs + Number of odd days in 74 NLYs.
= 24*2+72*1=74+48=122 odd days.
Now from January 2099 to May 2099, number of odd days = Jan (3)+ Feb (0)+ Mar (3) + Apr (2)+ May (3) = 11 odd days.
From 1st Jan 2001 to 31st May 2099, number of odd days = 122 +11 = 133/7= remainder 0, means 31st May 2099 is Sunday (Day before Monday). Therefore the first Sunday of June 2099 will be on 7th June 2099.

[garhisangwari]

Date+Century code+month code+year's last two digit+ (last two digit ÷4)

Divided by 7

Ye jyada easy hai

[priyankajoshi]

U r logic but pls look your comment section many people say so many wrong bcz ur method is too long we as student can not do such methids in exam day constarin of time.. So pls do something for that. 😊