Correct Answer - Option 2 : 84 km / h

**Given:**

Train length is 130m

The speed of the train is 120 km/h

Moving in the same direction of a train 140 m, and crosses in 27 seconds

**Concept used:**

When two objects move in the same direction speed is subtracted

When two objects move in the opposite direction speed is added.

Speed = Distance/Time

To convert speed km/h into m/s we multiply by 5/18 and vice versa

**Calculation:**

Total length is

⇒ 130 + 140 = 270 m

Let the speed of the other train be s km/h

Let Relative speed be r = 120 - s

⇒ r = 270/27 = 10 m/s

Convert speed into km/h multiply by 18/5

⇒ 10 × (18/5) = 36 km/h

Speed of the other train is

⇒ 36 = 120 - s

⇒ s = 120 - 36 = 84 km/h

**∴ The speed of the other train is 84 km/h**