Converting m/s to km/h — Aptitude Question
Converting m/s to km/h: A speed of 20 m/s is equal to how many km/h? Answer and worked solution on CodeKairo.
- Topic: Time, Speed & Distance
- Section: Quantitative Aptitude
- Difficulty: Easy
- Time target: 35 seconds
Question
A speed of 20 m/s is equal to how many km/h?
Options
- 54 km/h
- 60 km/h
- 72 km/h
- 80 km/h
Show the answer and the worked solution
Correct answer: C. 72 km/h
Worked solution
- m/s → km/h means multiplying by 18/5.
- 20 × 18/5 = 72 km/h.
Answer: 72 km/h.
The idea
m/s to km/h: multiply by 18/5. km/h to m/s: multiply by 5/18. Getting the direction wrong is the single most common error in this chapter.
Shortcut. 1 m/s = 3.6 km/h, so 10 m/s = 36 km/h and 20 m/s is double that: 72 km/h.
Common trap. 80 km/h — rounding the factor 3.6 up to 4 to save time (20 × 4); the exact 18/5 gives 72 km/h.