The speed of a train is 25m/sec.It takes 40sec to cross a platform of 700 m.What is the length of train. Share with your friends Share 0 Brijendra Pal answered this Hi, We know that Speed = distancetimeso here length that will train cross in 40 second is the total length of train + plateform so let train is x m long 25 = x+70040x+700 = 1000x = 300 m 1 View Full Answer Ashwadeep Raj answered this 650 m 0 Raj Kumar Singh answered this let the length of train = x meter -1