Question

What was the day of the week on 15 August 2013?

• A. Thursday
• B. Tuesday
• C. Wednesday
• D. Monday

Answer 1

Answer:

A. Thursday

Solution:

We’ll divide 2013 in different years

2000 years + 12 years + 2013 ( Jan + Feb + March + April + May + June + July + till 15 august)

There are 3 leap years and 9 non-leap years from 2001 to 2012. Therefore, no. of odd days in this period = 1

Also, 2013 is a non-leap year.

Thus, odd days in the given above years = [0 + 1 + (3 + 0 + 3 + 2 + 3 + 2 + 3 + 1)] mod 7

Total odd days = 18 and  18 ÷ 7 = 4 (remainder)

Days codes:

Sunday	Monday	Tuesday	Wednesday	Thursday	Friday	Saturday
0	1	2	3	4	5	6

Code 4 is for Thursday.

Hence, “Thursday” is the correct answer.