A broken clock shows the correct time twice a day, but a clock that is 5 minutes fast never shows the correct time. Why?
Hint
Think about what "broken" means for a clock.
Answer
A broken (stopped) clock shows the same time all day, which will be correct twice in 24 hours. A clock that's 5 minutes fast is always 5 minutes ahead of the actual time, so it never shows the correct time.