Choose Language

Select your preferred reading language
🇬🇧
English
🇮🇳
हिन्दी
Full View
NTPC Graduate Tier 1 2016 Shift 2 📅 02 Apr, 2016

If P travelled the first half of a journey at 40 km/hr and the remaining distance at 50 km/hr, what is the average speed of his travel?

A
44.44 km/hr
B
53.33 km/hr
C
45 km/hr
D
60 km/hr
Result Summary
Logo

APEDIA

NTPC Graduate Tier 1
2016 • 02 Apr, 2016 • Shift 2
If P travelled the first half of a journey at 40 km/hr and the remaining distance at 50 km/hr, what is the average speed of his travel?
Correct Answer
44.44 km/hr
Kinematic Principle: Average speed is not a simple arithmetic mean of the two speeds. Because different speeds are maintained over equal segments of distance, t......
💡 Analysis & Explanation
Kinematic Principle
Average speed is not a simple arithmetic mean of the two speeds. Because different speeds are maintained over equal segments of distance, the time spent traveling at the slower speed is longer.
Formula Application
For two equal halves of a journey traversed at speed 'x' and speed 'y', the harmonic mean formula for average speed applies: (2xy) / (x + y).
Variable Substitution
Let x = 40 km/hr and y = 50 km/hr.
Calculation Steps
Average Speed = (2 * 40 * 50) / (40 + 50) = 4000 / 90.
Final Output
4000 divided by 90 equals 44.444...
Conclusion
The average speed for the entire journey is precisely 44.44 km/hr.