Correct Answer - Option 2 : 198 km/h

Length of train = 300 m

Time is taken by train to pass a pole = 15 seconds

Time taken to cross another train of the same length = 8 seconds

**Calculations:**

Speed of the 1^{st} train = 300/15 = 20 m/s

Let the speed of 2^{nd} train be x

Relative speed = (20 + x) m/s

Length of 1^{st} train + length of 2^{nd} train = 300 + 300 = 600 m

In the second scenario the equation is

⇒ 600/(20 + x) = 8

⇒ 600 = 160 + 8x

⇒ 600 – 160 = 8x

⇒ 440 = 8x

⇒ x = 55 m/s

∴ Speed of the train = 55 × 18/5 = 198 km/h.

**The speed of the train is 198 km/h.**