Task: Question Answering
Input (English): Question: Distance between two stations A and B is 778 km. A train covers the journey from A to B at 84 km per hour and returns back to A with a uniform speed of 56km per hour. Find the average speed of the train during the whole journey?

 Option A: 69 km /hr

 Option B: 69.2 km /hr

 Option C: 67.2 km /hr

 Option D: 67 km /hr

 Option E: 65 km /hr
Output (English): Option C