Question

A train running at a speed of 54 km/h and crosses a electric pole in 11 seconds. If this train crosses the bridge then it takes 19 seconds more. then the length of the bridge is what percentage more/less than the length of the train?
1. 72.72%
2. 62.62%
3. 52.52%
4. 42.42%

Answer 1

Correct Answer - Option 1 : 72.72%

Given:

The speed of the train is 54 km/h

Concept:

Speed = Distance/Time

Calculation:

Let be assume length of the bridge is X m

⇒ The length of the train = 11 × 54 × (5/18) = 165 m

⇒ Time taken to crosses the bridge = 11 + 19 = 30 sec

⇒ 30 × 54 × (5/18)  = (165 + X)

⇒ 450 - 165 = X

⇒ X = 285 m

⇒ The required percentage = (285 - 165)/(165) × 100 = 72.72%

∴ The required result will be 72.72%.