A 1800 metres long train crosses a man walking in opposite direction in 10 seconds. If the speed of train is 8 times to the speed of man, then what is the speed of train?

576 km/hr 

Given :-

speed of train is 8 times to the speed of man

Let speed of man = x  m/sec

Speed of train = 8x m/sec

Relative speed ( When both moves in opposite direction ) = x + 8x = 9x m/sec

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

= \(\frac{1800}{10}\) = 180 m/sec

According to question ,

9x = 180

x = 20 m/sec

So , speed of train = 8x = 8 × 20 = 160 m/sec

160 m/sec = 160 × \(\frac{18}{5}\) km/h = 576 km/h