If 30 April 1983 was a Saturday, then what was the day of the week on 13 August 1989?

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 }

30 April 1983;

30 + 0 +0 + 83 + 20 = 133

remainder of \(\frac{133}{7}\) = 0

Therefore, the code of 0  is Saturday

Similarly,

13 Aug 1989;

13 + 03 + 0 + 89 + 22 = 127

remainder of \(\frac{127}{7}\) = 01

Therefore, the code of 01 is Sunday