If a train crosses a pole in 12 seconds while travelling at a speed of 45km/hr, then in how much time will the train cross a bridge of length 600m at same speed?

60 Sceond

Speed = \(\frac{Distance }{Time }\)

let the length of train be x

45 x \(\frac{ 5}{ 18}\) = \(\frac{ x}{ 12}\)

\(\frac{ 25}{ 2}\) =  \(\frac{ x}{ 12}\)

x = 150 m

Now, 

45 x \(\frac{ 5}{ 18}\) = \(\frac{\text{150 + 600}}{Time}\)

\(\frac{ 25}{ 2}\) = \(\frac{\text{750}}{Time}\)

Time = 60 seconds