A 250 – metre long train running at a speed of 100 km/h crosses another train coming from the opposite direction at a speed of 62 km/h in 10 seconds. What is the length of the second train?

Correct option is D

Given: 

Length of train = 250 meter

Speed of  train 1 = 100 km/h 

Speed of train2 = 62 km/h 
Relative speed = $$100 + 62 = 162 \, \text{km/h} = 162 \cdot \frac{5}{18} = 45 \, \text{m/s}.$$​

Time = 10 s

Formula Used:

$$\text{Relative length = Speed} \times \text{Time.}$$​

Solution: 

Applying the formula:

$$\text{Length of both trains = } 45 \times 10 = 450 \, \text{m}. \\ \ \\ \text{Length of second train = } 450 - 250 = 200 \, \text{m}.$$