A station platform 500 m long starts at the point where a bridge 1.7 km long ends. How long will a train 400 m long, travelling at 65 km/hr, take to cross the bridge and the platform completely?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 144 seconds
The train starts crossing when its front reaches the start of the bridge and finishes when its rear leaves the far end of the platform. So it covers the bridge, the platform and its own length.
Distance \(=1700+500+400=2600\) m
Speed \(\displaystyle =65\times\frac{5}{18}=\frac{325}{18}\) m/s
Time \(\displaystyle =2600\times\frac{18}{325}=8\times18=144\) seconds