900 metre long train crosses a 1200 metres long platform completely in 70 seconds. What is the speed of the train?

108 km/h

We know ,

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

Total distance covered by train = 1200 + 900 = 2100 m

Time taken = 70 seconds

Speed = \(\frac{2100}{70}\) = 30 m/sec

30 m/sec = 30 × \(\frac{18}{5}\) = 108 km/h

So , Speed of train is 108 km/h