Question

a train of length 50m is moving with a constant speed of 10m/sec.Calculate the time taken by the train to cross an electric pole and bridge of length 250m

Answer 1

time taken for whole train to cross 10 meters 50/10= 5sec 
time taken for crossing 250m= 250/10 = 25secs per 1m of train
time taken for whole train= 25x5= 125sec= 2 minutes 5 seconds