Question

A train passes a truck coming from the opposite direction in 9 sec. If the speed of the truck and the train is 90 kmph, then what is the length of the train?

1. 330 m
2. 450 m
3. 430 m
4. 300 m

Answer 1

Correct Answer - Option 2 : 450 m

Given:
Speed of the train = 90 km/h
Speed of the truck = 90 km/h
Train passes a truck coming from the opposite direction = 9 sec

Concept used:
When two bodies move in opposite direction, then
Relative speed = Sum of their speeds
Distance = Speed × Time
km/h × 5/18 = m/sec

Calculation:
Relative speed of the train and the truck = (90 + 90) km/h = 180 km/h
⇒ 180 × 5/18 = 50 m/sec
Let the length of a train be L.
⇒ L = 50 × 9 
⇒ L = 450
∴ The length of a train is 450 m.