Explanation:

To determine the day of the week for any given date, you can use Zeller's Congruence or a perpetual calendar. For 10 June 2011:

- 2011 is in the 21st century.

- Using Zeller's Congruence, you break the date into parts: day (10), month (6 for June), year (2011).

- Adjust if month is Jan or Feb by counting the month as 13 or 14 and decreasing the year by 1.

- Use the formula: $$h=(q+\lfloor \frac{13(m+1)}{5}\rfloor +K+\lfloor \frac{K}{4}\rfloor +\lfloor \frac{J}{4}\rfloor -2J)mod7$$

Where:

- $q$ is the day of the month (10).

- $m$ is the month number (6).

- $K$ is the year of the century (11).

- $J$ is the zero-based century (20).

Compute the day of the week:

- The formula gives a result corresponding to a day, where 0 = Saturday, 1 = Sunday, ..., 5 = Friday.

?? After computing, you find it lands on 5. Therefore, 10 June 2011 was a Friday.

Answer: 2. Friday