Air travel between cities of different time zones
Cities A and B are in different time zones. A is located 3000 km east of B. The schedule of an airline operating non-stop flights between A and B is as follows. (All the times indicated are local and on the same day). Departure from B 8 AM ; Arrival at A 3 pm; Departure from A 4 PM; Arrival at B 8 pm. Assume that planes cruise at the same speed in both directions. However, the effective speed is influenced by a steady wind flowing from east to west at 50 km per hour.
What is the time difference between A and B (in hours)?