If the 21st of June 2021 was Monday, what day of the week was it on t…

The 21st of June 2021 was Monday.

Remaining number of days in 2021 = 9 + 31 + 31 + 30 + 31 + 30 + 31 = 193

Divide 193 by 7 = 193/7 = 27 (Quotient), and 4 (Remainder)

Odd days in 2021 = 4days

Similarly, odd days in 2022 = 1day only

Now, the number of odd days in 2023 till 11 June => 3 + 0 + 3 + 2 + 3 + 4 = 15

Total number of odd days = 4 + 1 + 15 = 20

Divide 20 by 7; Remainder = 6, i.e., the required number of odd days = 6

So, on 11 June 2023, it will be Monday + 6 = Sunday

Thus, the 11th of June 2023 will be Sunday.