Case 1: They move towards each other. Relative speed = 85 km/h + 70 km/h = 155 km/h. Distance covered in 1 hour = 155 km. Remaining distance = 325 km - 155 km = 170 km.
Case 2: They move in the same direction (away from each other). Relative speed = 85 km/h - 70 km/h = 15 km/h. Distance between them = 325 km + 15 km = 340 km.
Case 3: They move in the same direction (towards each other's starting point). Relative speed = 85 km/h + 70 km/h = 155 km/h. Distance between them = 325 km - 155 km = 170 km.
Possible distances are 170 km and 340 km.