At 2:30 p.m., Cayson leaves his house and drives north to the stadium. He arrives at 5:00 p.m. Also leaving at 2:30 p.m., his brother Riley leaves his house and drives south to a lake. He arrives at 5:30 p.m. The driving distance from the stadium to the lake is 385 mi. Cayson and Riley drove at the same speed. What was their speed?