A train travels 210 km in 3 hours and 270 km in 4 hours.find the average speed of train.	Choose the most appropriate option:
A) 80 kmph	B) 69 kmph	C) 70 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 = 210 + 270 = 480 km thus , total speed = 7 hrs or , average speed = 480 / 7 or , 69 kmph . answer : b"
Answer: B