Friday, April 3, 2009

Word Problem on Speed

I have a word problem that I cannot solve. The problem is: Carson and Daniel started driving from the same place but in opposite directions. After 5 hours, they were 60 km apart. Carson's average speed was 12 km/h less than Daniel's. What was Daniel's average speed ?
A teacher in Indonesia
Every hour, who travels a longer distance? Daniel, isn't it? How much further? That is correct - 12 km every hour. That means after 5 hours, Daniel has travelled 60 km more than Carson. Since they are 60 km apart after 5 hours - what does that mean? It seems that Carson was not moving at all and Daniel was travelling at an average speed of 12 km/h - which seems a little slow!

Is there a flaw in the reasoning? Or the problem was not well-posed. Comments?


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