Given: Speed of Neelam while travelling 60 km = 30 km/h Speed of Neelam while returning through 10 km shorter route = 25 km/h Concept Used: Average speed = Total distance covered/Time Taken The unit of speed is m/s or km/h or m/min. Calculation: Let time taken by Neelam to travel from Phulpur to Rajapur be T1 We know that, T1 = Distance covered/Speed ⇒ T1 = 60/30 ⇒ T1 = 2 hours again, let the time taken by Neelam to travel from Rajapur to Phulpur through 10 km shorter route be T2 T2 = Distance covered/Speed ⇒ T2 = (60 – 10)/25 ⇒ T2 = 50/25 ⇒ 2 hours So, the Average speed of Neelam for the entire journey ⇒ Total distance travelled/Total time taken ⇒ (60 + 50)/(2 + 2) ⇒ 110/4 ⇒ 27.5 km/h ∴ The Average speed of Neelam for the entire journey is 27.5 km/h