Answer: 700

Explanation:
The century divisible by 400 is a leap year.
The year 700 is not a leap year.

Answer: Friday

Explanation:
If 1st January 1980 is a Sunday then what will be the day on 9th September 1985
From 1980 to 1984 there are 3 ordinary years and one leap year
Number of odd days = 3+2=5 odds
1st January 1985 to 9th September 1985 no of days = 31+28+31+30+31+30+31+31+9= 252 = 0 (221/7) odd days
Therefore total number of odd days = 5 + 0 = 5 odd days , which is a Friday

Answer: Thursday

Explanation:
From Friday, 62 days = 8 weeks and 6 odd days. Therefore the day is Thursday

Answer: 2012

Explanation:
Count the number of days from 2005 onwards to get 0 odd day.
Year - Odd days
2005 - 1
2006 - 1
2007 - 1
2008 - 2
2010 - 1
2011 - 1
= 7 or 0 odd day
Hence, Calendar for the 2005 is the same as that for the year 2012.

Answer: Friday

Explanation:
January 12, 1979 = 1979 years + 12 days
1600 years : 0 odd days
300 years : 1 odd day
78 years have 19 leap years + 59 ordinary years i.e. 38 + 59 i.e. 97 i.e. 6 odd days
12 days of January have 5 odd days
Total number of odd days = 0 + 1+ 6+5 = 12 i.e. 5 odd days
∴ the day on January 12 , 1979 was a Friday

Answer: 1^st, 8^th , 15^th , 22^nd , 29^th

Explanation:
Find the day on 1^st April 2001, 2000 years contain 2 odd days
Jan Feb March April
31 + 28 + 31 + 1
= 91 days = 13 weeks 0 day = 0 day
Sunday fell on 1^st, 8^th, 15^th, 22^nd and 29^th of April 2001.

Answer: Wednesday

Explanation:
17th June, 1998 = (1997 years + Period from 1.1.1998 to 17.6.1998)
Odd days in 1600 years = 0
Odd days in 300 years = (5 x 3) 1
97 years has 24 leap years + 73 ordinary years.
Number of odd days in 97 years ( 24 x 2 + 73) = 121 = 2 odd days.
Jan. Feb. March April May June
(31 + 28 + 31 + 30 + 31 + 17) = 168 days
168 days = 24 weeks = 0 odd day.
Total number of odd days = (0 + 1 + 2 + 0) = 3.
Given day is Wednesday.

Answer: Sunday

Explanation:
2000 yrs have 2 odd days.
Year - Odd days
2001 - 1
2002 - 2
2003 - 1
2004 - 2
2005 - 1
2006 - 1
2007 - 1
2008 - 2
2009 - 1
= 11 odd days = 4 odd days
1^st Jan, 2010 has 1 odd day. Total Number of odd days = (2 + 4 + 1) = 7 = 0
Hence, 1^st Jan, 2010 will be a Sunday.

Answer: Saturday

Explanation:
100 years have 5 odd days. Hence the last day of 1st century is a Friday.
200 years have 10 odd days or 1 week + 3 odd days. Hence, the last day of the 2^nd century is a Wednesday.
300 years have 15 odd days or 2 week + 1 odd day. Hence, the last day of the 3^rd century is a Monday.
400 years have 0 odd days. Hence, the last day of the 4th century is a Sunday.

Answer: Monday

Explanation:
The year 2004 being a leap year, has 2 odd days.
So, the day on 8^th march 2005 will be two days beyond the day on 8^th March 2004. But 8^th march 2005 is Wednesday. So, 8^th march 2004 is a Monday.