Explanation:

- Rohan started on 3rd June, solving 3 problems on the first day.

- Each day he increases the number of problems by 3 (3, 6, 9,...).

- This pattern forms an arithmetic sequence: \(a_n = 3n\), where \(n\) is the day since he started.

- By 25th June, he would have practiced for 23 days since 3rd June.

- Using the sequence \(a_n = 3n\), on the 23rd day, he solves \(3 \times 23 = 69\) problems.

- None of the given options (57, 66, 63) are correct.

So, the correct answer is option:4- None of these.

Your answer is right