Mr. Smith grumbles about bad time-keeping trains like everybody else. On one particular morning he was justified, though. The train left on time for the one hour journey and it arrived 5 minutes late. However, Mr. Grumper's watch showed it to be 3 minu
The station clock is 3 minutes fast. The morning journey took 65 minutes, and the evening journey therefore took 52 minutes. So the train arrived 57 minutes after it should have left, that is, 3 minutes early.