Two trains were running in the same direction at 90 km per hour and 70 km per hour respectively. The faster train passed a man standing in the slower train in 18 seconds. The length of the faster train is
- AOption (a)
80 metres
- BOption (b)
100 metres
- COption (c)
120 metres
- DOption (d)
150 metres
View answer & explanationHide answer & explanation
Correct answer
100 metres
Why this answer is correct
Given:
Two trains were running in the same direction at 90 km per hour and 70 km per hour respectively. The faster train passed a man standing in the slower train in 18 seconds.
Concept Used:
length of faster train can be determined by calculating the relative speed of the train
Formula Used:
relative speed of train = (speed of faster train - speed of slower train) [for same direction]
Calculation:
⇒ relative speed of train = (90 - 70)km/hr = 20 km/hr = 20 × 5/18 m/s
⇒ length of faster tain = 20 × 5/18 × 18 = 100 m
∴ required length of the faster train = 100 m