PR 4 # 16
 

Two men are walking towards each other at the side of a railway. A freight train overtakes one of them in 20 seconds and exactly ten minutes later meets the other man coming in the opposite direction. The train passes this man in 18 seconds. How long after the train has passed the second man will the two men meet? (Constant speeds are to be assumed throughout.)

It looks like nonsense because of all the ambiguities. I got two answers, one of which looks correct and one which looks like it was a bullet train. The one that looks like nonsense says about 3 hours.

[quote]A freight train overtakes one of them in 20 seconds and exactly ten minutes later meets the other man coming in the opposite direction.[/quote]Assuming this means 10 minutes gap between the rear of the train passing the first man and the head of the train meeting the second man then I get the answer [spoiler]5562 seconds (1 hour, 32 minutes, 42 seconds). Length of train, speed of walking (even backwards), speed of train all make no difference to the result[/spoiler].

[QUOTE=Wacky]Two men are walking towards each other at the side of a railway. A freight train overtakes one of them in 20 seconds and exactly ten minutes later meets the other man coming in the opposite direction. The train passes this man in 18 seconds.[/QUOTE]
I assume that you mean that it takes 20 seconds for it to completely pass the first man (the equivalent of the 18), not that in 20 seconds from an instantaneous start that it intially arrives at his location.
If the former the problem is ok, if not.....:unsure: