Sally left Sciville at 10:18 am. She walked at a constant speed and arrived at Phystown at 1:30 pm. On the same day, Bill left Phystown at 9 am. Bill walked the same route in the opposite direction at a constant speed. Bill arrived at Sciville at 11:40 am. The road crosses a wide river. By coincidence, both arrived at the bridge on opposite sides of the river at the same instant. Sally left the bridge 1 minute later than Bill. At what time did they arrive at the bridge