If 01 February 2011 was Tuesday, then what was the day of the week on 01 January 2012?

Sunday

Using Code Method :-

\(\frac{Date+Month code+Year code+Last 2 digits of yr+Leap yrs till given yr}{7}\)

( Note: Remainder of the above sum will be the code of week day }

01 Feb 2011;

01 + 04 + 06 + 11 + 02 = 24

remainder of \(\frac{24}{7}\) = 03

Therefore, the code of 03 is Tuesday

Similarly,

01 Jan 2012;

01 + 0 + 16 + 12 + 03 = 22

remainder of \(\frac{22}{7}\) = 01

Therefore, the code of 01 is Sunday