The length of the bridge, which a train 130 metres long and travelling at 45 km/hr can cross in 30 seconds, is:

We are given the following:

• Length of the train = 130 meters
• Speed of the train = 45 km/h
• Time to cross bridge = 30 seconds

Step 1: Convert speed from km/h to m/s Speed = 45 × (5 / 18) = 12.5 m/s

Step 2: Calculate total distance covered in 30 seconds Distance = Speed × Time = 12.5 × 30 = 375 meters

Step 3: Subtract train length to get bridge length Bridge length = 375 – 130 = 245 meters

Answer: The bridge is 245 meters long.