Question

A train of length 287 m, running at 80 km/h, crosses another train moving in the opposite direction at 37 km/h in 18 seconds. What is the length of the other train?
1. 285 m
2. 300 m
3. 298 m
4. 289 m

Answer 1

Correct Answer - Option 3 : 298 m

Given:

Length of first train = 287 m

Speed of first train = 80 km/h

Speed of second train = 37 km/h

Time in which both trains cross = 18 secs

Formula Used:

1 km/hr = (5/18) × m/s

For trains moving in opposite direction,

v₁ + v₂ = (l₁ + l₂)/t

where, v₁ → Speed of train 1, v₂ → Speed of train 2, l₁ → Length of train 1

l₂ → Length of train 2, t → Time at which both trains meet

Calculations:

Let the length of second train be l m.

Now, v1 + v2 = (l1 + l2)/t

⇒ (80 + 37) × (5/18) = (287 + l)/18

⇒ 117 × (5/18) × 18 = 287 + l

⇒ 585 = 287 + l

⇒ l = 298 m

∴ The length of other train is 298 m.