A train travels 240 km in 3 hours and 450 km in 5 hours.find the average speed of train.
Options:
A) 80 kmph B) 60 kmph C) 86 kmph D) 90 kmph E) none of these

Rationale: "as we know that speed = distance / time for average speed = total distance / total time taken thus , total distance = 240 + 450 = 690 km thus , total speed = 8 hrs or , average speed = 690 / 8 or , 86 kmph . answer : c"
Answer: C