The actual time is 04:00. Here's how I calculated it: 1. The clock shows 3:45, but it's 15 minutes slow. So, the actual time is 15 minutes later than 3:45, which is 4:00. 2. The statement "The actual time is a quarter past an hour" confirms this, as a quarter past an hour refers to 15 minutes after the hour, which in this case is 4:00.