Two trains are moving in opposite directions at speeds of 110 km/h and 140 km/h. The length of one train is 140 m. The time taken by them to cross each other is 5 seconds. The length (in m) of the other train, correct to 2 decimal places, is:

Correct option is D

Given:
​Speed of train 1, v₁ = 110 km/h
​Speed of train 2, v₂ = 140 km/h
​Length of train 1, L₁ = 140 m
​Time taken to cross each other, t = 5 seconds
​Length of train 2, L₂ = ? 
​Formula Used:
​Relative speed when trains move in opposite directions: v₁ + v₂
​Distance covered when crossing each other = L₁ + L₂
​​$$\text{Time} = \frac{\text{Distance}}{\text{Speed}}$$​​​
​Convert speeds from km/h to m/s:
​​$$v \, \text{(m/s)} = v \, \text{(km/h)} \times \frac{5}{18}\\$$​​​
​Solution:
​Relative speed = $$(110 + 140) \times \frac{5}{18} = 250 \times \frac{5}{18} \, \text{m/s}\\$$​​​
​Distance covered in 5 seconds:
​​$$\text{Distance} = \text{Speed} \times \text{Time} = 250 \times \frac{5}{18} \times 5 = 347.2222 \, \text{m}\\$$​​​
​$$L_1 + L_2 = 347.222\\L_2 = 347.22 - 140 = 207.22 \, \text{m}\\$$​​​
​The length of the other train is 207.22 meters.​