Two trains move in the same direction at $72$ km/h and $54$ km/h. Their relative speed is:

Question

Two trains move in the same direction at $72$ km/h and $54$ km/h. Their relative speed is:

Option A

12 km/h

Option B — Correct answer

18 km/h

Correct choice.

Option C

24 km/h

Option D

126 km/h

Explanation

For the same direction, subtract the speeds: $72-54=18$ km/h.

Chapter Mock 8: Speed, Time and Distance