A train overtakes two persons who are walking in the same direction in which the train is going at the rate of 2 kmph and 4 kmph, and passes them completely in 9 and 10 seconds respectively. The length of the train (in metres) is :
A train overtakes two persons who are walking in the same direction in which the train is going at the rate of 2 kmph and 4 kmph, and passes them completely in 9 and 10 seconds respectively. The length of the train (in metres) is :