Two trains running in the same direction at 60 km/h and 40 km/h. A passenger in the slower train observes the faster passes in 15 seconds. Length of faster train?
A) 83.3 m
B) 100 m
C) 125 m
D) 250 m
Explanation
Relative speed = 20 km/h = 50/9 m/s. Length = 50/9 × 15 = 83.3 m.