Our man Ostap was going home from Kiev. He rode halfway by train – fifteen times as fast as he goes on foot. The second half he went by ox team. He can walk twice as fast as that. Would he have saved time if he had gone all the way on foot? If so, by how much?
Answer
Yes. He took as much time for the second half of his trip as the whole trip would have taken on foot.
So no matter how fast the train was, he lost exactly as much time as he spent on the train. He would have saved 1⁄30 of the time by walking all the way.