Prova travels a distance of 9 km from her house to the school by auto-rickshaw at 18 km/hr and returns on rickshaw at 15 km/hr. Find the average speed for the whole journey.

• ক 16.3 km/hr ✅ সঠিক উত্তর
• খ 12.2 km/hr
• গ 26.6 km/hr
• ঘ 19.8 km/hr