For each day at sea a sailor is paid a fixed sum. For each day ahead of the scheduled arrival time, he gets twice the regular daily earnings. If the total time at sea was scheduled for 20 days and a sailor earned a total of 3,850 dollars for the entire trip, how many days ahead of schedule did the ship arrive?
1. If the ship had arrived one day ahead of the schedule, the sailor would have earned 4,200 dollars.
2. The sailor's regular daily earnings were $175.