If 29^th September 2015 was a Tuesday, then what was the day of the week on 28th September 2019?

Saturday

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 }

29 Sep 2015;

29 + 06 + 06 + 15 + 03 = 59

remainder of \(\frac{59}{7}\) = 03

Therefore, the code of 03 is Tuesday

Similarly,

28 Sep 2019;

28 + 06 + 06 + 19 + 04 = 63

remainder of \(\frac{63}{7}\) = 0

Therefore, the code of 0 is Saturday