“The Mail Plane”: Solution
Solution to The Mail Plane:
The motorcyclist would have taken 20 minutes to go from where he met the horseman to the airport and back. Thus he was 10 minutes from the airport when he met the horseman. These 10 minutes plus the 30 minutes the horseman had been riding before they met makes 40 minutes the plane was ahead of schedule.
From B.A. Kordemsky, The Moscow Puzzles, 1956.
