Train A passes an electric pole in 15 seconds, moving at 60 km/h. It crosses train B moving in the opposite direction at 48 km/h, in 19 seconds. What is the length (in m) of train B?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 320.
Given:
Train A passes an electric pole in 15 seconds, moving at 60 km/h
Train A crosses train B moving in the opposite direction at 48 km/h, in 19 seconds
Formula used:
Speed = Distance/Time ----- (1)
Calculations:
60 km/h = 60 × 5/18 = 50/3 m/s
48 km/h = 48 × 5/18 = 40/3 m/s
According to the question;
Length of train A = 50/3 × 15 = 250 m
Relative speed = 50/3 + 40/3 = 90/3 = 30 m/s
Length of both trains = 30 × 19 = 570 m
Length of train B = 570 - 250 = 320 m