A train moves from P to Q at an average speed of 90km/h and immediately returns from Q to P through the same route at an average speed of 45km/h. Find the average speed for the entire journey
- 55.00km/h
- 60.00km/h
-
67.50km\h
- 75.00km\h
The correct answer is: C
Explanation
Average speed from P to Q = 90km\hAverage speed from O to P = 45km/h
Average for the entire journey = 90 + 45
\(\frac{135}{2}\) = 67.50 km/h