If 21^st June 2007 was a Thursday, then what was the day of the week on 21^st June 2011?

Tuesday

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}

21 Jun 2007;

21 + 05 + 06 + 07 + 01 = 40

remainder of \(\frac{40}{7}\) = 05

Therefore, the code of 05 is Thursday

Similarly,

21 Jun 2011;

21 + 05 + 06 + 11 + 02 = 45

remainder of \(\frac{45}{7}\) = 03

Therefore, the code of 03 is Tuesday