I have the following puzzle I'm trying to solve:
"A man lost on the Nullarbor Plain in Australia hears a train whistle due west of him. He cannot see the train but he knows that it runs on a very long, very straight track. His only chance to avoid perishing from thirst is to reach the track before the train has passed. Assuming that he and the train both travel at constant speeds, in which direction should he walk?"
I'm not quite sure what to do here. Given what the actual train tracks look like I'll assume that they are a straight line from east to west (from left to right). But where is the man? Above or below this line? Also, the train might be out of reach, or am I missing anything? Thanks for helps.