Jatin was trying to take a short cut through a very narrow tunnel when he heard the whistle of an approaching train behind him.
Having reached three-eights of the length of the tunnel, he could have turned back and cleared the entrance of the tunnel running at 10 km per hour just as the train entered.
Alternatively, if he kept running forward, the train would reach him the moment he would jump clear of the tracks.
At what speed was the train moving?