A train 150 m long is running at a speed of 90 kmph. Time taken by the train to cross a tree is :

3 sec 4 sec 6 sec 8 sec

6 sec

Speed = \(\frac{ Distance}{ Time}\) Time =  \(\frac{ Distance}{ Speed}\) Speed = 90 x \(\frac{5 }{18 }\) = 25 m/s Time =  \(\frac{ 150}{ 25}\) Time = 6 seconds