If 31 December 2003 was a Wednesday, then what was the day of the week on 7 March 2005?

Monday

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 }

31 Dec 2003;

31 + 06 + 06 + 03 + 0 = 46

remainder of \(\frac{46}{7}\) = 04

Therefore, the code of 04 is Wednesday

Similarly,

07 March 2005;

07 + 04 + 06 + 05 + 01 = 23

remainder of \(\frac{23}{7}\) = 02

Therefore, the code of 02 is Monday