In the above image a boy is at a point in the tunnel AB, dividing it in the ratio 2:3. A train is approaching the side A with a constant speed. Now at a particular instant of time, the situation is such that if the boy runs towards A the train enters the tunnel just as he come out. And if he decides to go towards B, then the train and the boy both will come out at the same time. Our job is to find the ratio between their speeds. The real task is doing this by the most elementary method that is possible.