Speed = (distance covered) / (time to cover the distance)
Distance covered = (end distance) minus (start distance)
Distance covered = (124 - 74) = 50 miles
Time to cover the distance = (3:45 - 3:00) = 45 minutes or 0.75 hour
Speed = (50 miles) / (0.75 hour)
Speed = 66 and 2/3 mph