A car travles 180 km from A to B at 60 kilometers/hour and returns from B to A along the same route at 90 kilometers/hour. The average speed in kilometers per hour for the round trip is:

প্রশ্নঃ A car travles 180 km from A to B at 60 kilometers/hour and returns from B to A along the same route at 90 kilometers/hour. The average speed in kilometers per hour for the round trip is: