The length of the bridge, which a train 150 meters long and travelling at 45 km/h can cross in 30 seconds, is-

Question: The length of the bridge, which a train 150 metres long and travelling at 45 km/h can cross in 30 seconds, is-

Solution:
Given,
Speed = 45 km/hr
= 45 × (5/18) m/sec
=25/2 m/sec
Time = 30 sec

Let, the length of bridge = x metres

Now
(150 + x)/30 = 25/2
⇒ 300 + 2x = 750
⇒ 2x = 750 - 300
⇒ 2x = 450
⇒ x = 450/2
∴ x = 225