On Wed, 20 Jan 2010 08:11:28 -0800, Darren New wrote:

> Warp wrote:
>>   I have hard time parsing that question.
> 
> It *is* messed up. The usual question is something like
> 
> You have a race two miles long. For the first mile, one car goes 60MPH
> and the other goes 30MPH. How fast does the other car have to go to
> finish the race at the same time as the one going 60MPH?

Even then it doesn't parse correctly, because they've given you the 
speeds for both cars - so asking how fast the slower car should go 
doesn't make sense, because you've been told how fast it is going.

And I'm not sure that discarding the length of the track allows the 
question to be answered even then.  I assume they're asking about when 
the two cars would cross the finish line at the same time, not when they 
would finish at the same time (since the slower car would clearly be laps 
behind the faster car).  Assuming both are measured at a running start 
(ie, at speed), one car going half the speed of another should cross the 
finish line of a closed track at the same time every 2 laps.  I think 
that's the answer they're going for.

Jim

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