A car travels at 50 km/h for 2 hours and then travels at 80 km/h for 4 hours. What is the average speed of this car?
(A) 65 km/h
(B) 70 km/h
(C) 75 km/h
(D) 66 km/h
(E) None of the above
Distance covered in the first 2 hours = speed x time km
Distance covered in the next 4 hours = speed x time km
Average Speed = (Total distance/Total time) km/h
Hence, the answer is (B).