The distance between two towns A and B is 545 km. A train starts from town A at 8 A.M. and travels towards town B at 80 km/hr. Another train starts from town B at 9: 30 A.M. and travels towards town A at 90 km/hr. At what time will they meet each other?

Train A travels alone from 8 AM to 9:30 AM = 1.5 hours at 80 km/hr = 120 km. Remaining distance = 545 - 120 = 425 km. Relative speed when both travel = 80 + 90 = 170 km/hr. Time to meet after 9:30 AM = 425/170 = 2.5 hours. Meeting time = 9:30 AM + 2.5 hours = 12:00 PM. Option C is correct. Options A (11:30) misses 0.5 hours, B (12:30) is 0.5 hours late, D (1:00) is 1 hour late, E (11:00) is 1 hour early.