Rogelio's watch stopped at 2:00 p.m. He started it without changing the time and went to visit
a friend. When he arrived, he was told that it was 4:10 p.m. He stayed with his friend for exactly two hours and walked back home, taking the same amount of time as he had left. He went to the clock, which at that moment read 4:40 p.m., and set it to the correct time. How could he have known?
Rogelio, what was the exact time? What was the exact time?